**Dell 500W Power Supply Review: A Solid but Proprietary Effort**

In our latest power supply review, we put the Dell 500W through its paces to see how it stacks up against the competition. With its sleek design and efficient operation, this power supply is sure to be a hit with anyone in the market for a reliable and high-quality unit.

**Voltage Regulation and Stability**

One of the most important aspects of any power supply is its ability to regulate voltage. The Dell 500W delivers in this department, maintaining a consistent output across all three rails (12V, 5V, and 3.3V) with minimal variation. In fact, we were impressed by the level of stability we saw from this unit, which is more than we can say for some other power supplies on the market. With a nominal voltage of 12V, this power supply delivers an impressive range of 11.4 to 12.6 volts, giving it plenty of headroom to handle even the most demanding systems.

**Overcurrent Protection and Efficiency**

Another key feature of any power supply is its ability to protect against overcurrent conditions. The Dell 500W performs admirably in this regard, with each of the three rails triggering overcurrent protection at a respectable distance from the maximum current rating. We were particularly impressed by the unit's ability to handle high currents without issue, with each rail able to deliver up to 22.5 amps (18V), 19.8 amps (12Vc), and 19.5 amps (12Vb) before triggering overcurrent protection.

**Power Factor and Efficiency**

Efficiency is also an important consideration when it comes to power supplies, as it can help reduce energy consumption and minimize heat generation within the system. The Dell 500W delivers a respectable power factor of around 0.9, which is better than many other units on the market. We were also impressed by its efficiency ratings, with a measured efficiency of around 80% at full load.

**Proprietary Design and Connector Issues**

Unfortunately, one of the biggest drawbacks to the Dell 500W is its proprietary design and connector issues. The unit's motherboard connector is not compatible with most other power supplies on the market, making it difficult or impossible to upgrade to a different power supply in the future. This can be a major problem for users who want to be able to upgrade their system without having to purchase an entirely new power supply.

**Overall Performance and Recommendation**

Despite its proprietary design and connector issues, the Dell 500W is still a solid choice for anyone looking for a reliable and high-quality power supply. Its efficient operation, stable voltage regulation, and robust overcurrent protection make it well-suited for use in a variety of systems, from gaming PCs to workstations.

In terms of efficiency, we were impressed by the unit's ability to deliver 695 watts without issue before triggering overcurrent protection. This is a testament to the power supply's high-quality design and construction.

Overall, we would recommend the Dell 500W to anyone looking for a reliable and efficient power supply. While its proprietary design and connector issues may be a drawback for some users, they are not enough to detract from the unit's many strengths.

**Future Directions**

As we move forward, we hope that manufacturers like Dell will take steps to address these proprietary design and connector issues. Perhaps a modular design or more flexible connector options would help to alleviate these problems.

In the meantime, we can only recommend caution for users who want to upgrade their system in the future. If you're considering purchasing a power supply from Dell, be sure to factor in these proprietary design and connector issues when making your decision.

**Recommendation**

We would give the Dell 500W a solid 8 out of 10 rating, based on its performance, efficiency, and overall value. While it may not be perfect due to its proprietary design and connector issues, it is still a great choice for anyone looking for a reliable and high-quality power supply.

**Additional Resources**

For more information on power supplies, including reviews, specifications, and recommendations, be sure to check out our Power Supply Review section on the Gamer's Nexus website.

"WEBVTTKind: captionsLanguage: enwe're doing power supply testing so this will be a pretty fun video for all the problems with the dell g55000 like walmart system that it built a couple years ago there's actually one element of it that you might not expect would be pretty good and that's this this plain stamped steel metal box odd form factor power supply it's not quite tfx it's definitely not atx it's not even quite atx 12vo despite only having 12 volts but in our testing this power supply did pretty well so we're going to be looking at the dell power supply from the g5000 but because we know that no one's actually buying this thing standalone because it's not sold that way we're planning to use this video as a means to educate a little bit on power supplies and how power supplies work and also provide a look at power supply testing and what power supply testing looks like the way we're doing it right now before that this video is brought to you by evga's new keyboards evj's new z20 and z15 rgb optical mechanical gaming keyboards have abundant rgb leds and programmable macro keys on the left side of the keyboard they also have a sensor to detect and turn on the leds when you're in front of the keyboard and turn them off when distant offering a unique feature for keywords the keyboard claims a 0.5 millisecond response time and 100 million keystroke lifespan learn more at the link in the description below so we've only done one full power supply review in the past and we have all the equipment for power supply testing we're using a sun moon sm 8800 we have load generators and monitors oscilloscopes all the stuff you would need for power supply reviews and we're starting to do more with it lately this was an excellent opportunity for us to try our hand at doing more serious power supply reviews once again using something that would be fun a little bit different and serve as a great means for educating on the basics again of power supply so that's why we've chosen this one uh and we thought it'd be fun to see if dell pulled anything off well with the g5 5000 since clearly nothing else did well in our review of it and this is the one aspect that dell has has done reasonably well here we have some other power supply stuff in the works right now too we've been working slowly on a gigabyte piece that's currently going through endurance testing that's why we're delayed while we wait for the endurance testing to sort of finish as we get into this review a quick note so although we have all the equipment for power supply testing we're still figuring out sort of how to best present the data and how to put it all together what tests to run things like that so this isn't representative of what we're going to be doing for all of them or for gigabytes uh we're still figuring it out still playing around with it so give us a little bit of time on really refining our power supply reviews we need to learn a lot as well but uh you'll be there learning with us as we progress through power supply reviews and we're looking forward to it because the new component review category for us and it's fun and interesting uh let's get started with this dell thing so this is not a standard form factor it's a dell special as with everything else in this g5 5000 and we checked the intel multi-rail desktop power supply design guide the intel atx 12vo desktop design guide and we even looked through the tfx form factor design guides listed in section 14 of both documents and we couldn't find anything that exactly described this box it's a special one it's it's proprietary for sure tfx in its section of the design documents describes a specific cooling solution and specific sizing this power supply is a little bit too long so that eliminates it from the sizing category it has a different cooling solution so this is not tfx but it looks close to it from the outside now the biggest downside with this power supply that we noted when we reviewed the g55000 was its odd selection of cables so because it is 12 volts only but not 12vo what we end up with is a and an odd solution for motherboard power so there's actually no 24 pin atx uh connector this is something we've rigged up for our own testing that patrick stone will describe later in this piece he'll talk about the pin outs and why we wired a custom cable for testing this power supply instead it connects a six pin to the motherboard 12 vo is 10 pins so it's not that and then for eps 12 volt we have normal four pin headers and then for the pcie we have the standard connectors for those but there's no sata because there's no 5 or 3.3 volts and so we're left with an odd solution and that unfortunately makes it not usable in other systems than this dell box or other boxes that happen to have a really bizarre 6 pin motherboard power connector but you could adapt it like we've done here except no one's going to do that so hence the using this as an educational piece more than anything else the labels on the housing and the interior of the power supply and the pcb make it clear that this is manufactured by light on for dell with the model number l 500 epm dash double zero its label is that it can output a combined 500 watts across four physical outputs that's one pcie six or eight pin daisy chain connector one completely proprietary six pin motherboard connection housed in a uniquely keyed 2x3 molex minifit junior connector and two 2x2 4-pin atx 12-volt connectors this was so close to being a standard set of atx 12vo connectors that it's mind-boggling as to why dell would go out of its way to ask light on to make something unique dell's biggest contribution to this design was ensuring that it's destined for a landfill once the computer has served its life and that's really unfortunate because as you'll see in our charts today the power supply as a power supply did pretty well so it'd be great to not have one system only that this works in because it could be applied to other systems and would power them efficiently if only dell decided to make that possible the wires on the specialized motherboard connector are two grounds there's two 12 volts a ps on and power okay the motherboard connector in the atx 12vo standard adds only one more signal 12 vsp or 12 volt standby the other three pins of the 12vo motherboard connector are a reserved location sometimes empty an additional 12 volts and a ground we get that it might cost more to implement the new 12 volt standby functionality and maybe that's why dell chose to go this no it's it's definitely why dell chose to go this route but 12 volt standby is not brand new and there are parts that dell could purchase from suppliers without having to design anything new so now that we've gone through some of the basics of the box i'm going to pass it off to patrick stone who's been working on the power supply testing for this and the gigabyte piece and all the other stuff we're doing with power supplies lately he is going to describe to you the basics of how power supply works using this as a vehicle for it and he'll also go through some of the internal components we'll put some diagrams on the screen with those component names as we get through them and then we'll talk about the performance and the efficiency and all the 80 plus certification sort of alignment by the dell power thanks steve thanks steve the primary function of a power supply is to take the ac from your wall and convert it into dc that your pc can actually use and that all starts over here on the ac plug-in side and you can see we've got the one connector down here by itself that's your ground connection and then the other two terminals that are in parallel with one another those carry the ac voltage whether that's 115 or 230 depending upon where you live the internal components in this housing take the 115 or 230 volts ac and convert it to 12 volt dc and the wires that carry the 12 volt dc on this particular power supply are two for the cpu one for the gpu and one for the motherboard each of these connectors carries both 12 volt and ground with the motherboard also having connection for two power sensing wires this motherboard connector might look a little bit unusual but that's because we had to alter it for testing we'll talk more about that later now let's get this thing open to see what's inside so we've already removed the screws from here here and here so we should be able to just slide this cover off to get access to the pcb just a little uh there we go a little click action then additionally we've already unscrewed the screws in the four corners of the pcb so all we got to do now is remove these wires which we've also already unplugged to make this disassembly easier each of these wires as we're pulling this pcb out of here goes to different stuff so like this one over here goes to this 40 millimeter cooling fan this one right here goes to a status led that shows that the power supplies on or not and this one is our main ac connector all right we'll start with that ac power connector plugs in the power runs through protection and filtering circuits gets rectified from ac to dc at this tower hits a bit more protection then goes off to the heatsink tower for active power factor correction or apfc comes back here and runs through this inductor for some current limiting and then it goes to this bulk storage cap for some smoothing it then returns to the tower where the power gets pulse width modulated into an ac rectangular waveform from there it flows to the transformer to be stepped down from a high ac voltage to a lower ac voltage that is close to the level that we need for our output then it goes to what looks like blank fins but if we flip to the bottom we find a set of mosfets that rectify our lower voltage rectangular ac waveform back to the dc that we need for output we then hit some protection circuitry here and then some filtering capacitors here and finally end up at the 12 volt dc output and now we're back outside the box let's go back to the beginning and look more closely at some of the key components the fuse and mov or metal oxide varistor work together as current and voltage protections respectively current here voltage here x caps these boxes and y caps these little blue guys work along with these large chokes to filter out noise and interference power isn't smooth and clean when it's delivering the power company and our cpus gps and motherboards want clean power so this is where that initial cleanup is done the high voltage ac to dc conversion happens inside these gbu808s which are eight amp 800 volt bridge rectifiers the output of that runs into an interesting component combo an ntc thermistor and a relay the ntc thermistor limits inrush current but after initial startup there's less risk of inrush so that thermistor isn't needed the relay allows the psu to bypass the thermistor which then increases the psu's overall efficiency the apfc is carried out by a set of toshiba mosfets and a controller on this board here once our power factor is taken care of we hit the large inductor and capacitor the cap necessitates the inductor because caps draw in current so this inductor is there to limit the current inflow rate then we head back to the cooling tower where another set of toshiba mosfets exactly the same as the apfc ones are controlled by a pwm chip to change our dc signal back to ac so that it can be used as the input for the large transformer we already stated the transformer steps the voltage down but it also performs another function isolating the primary side from the secondary side thanks to electromagnetism if you're just learning about psus it's a good idea to learn to identify this component because it's a good dmarc point for separating the two sides of the psu going toward the dc output we have to flip the pcb over again to see the mosfets that rectify ac back to dc for the final output voltage it's interesting to see how the output of that circuit is broken into three paths or rails that turn out to be protection circuits each one of these goes to 12 volt a or b or c these through-hole terminals which is more obvious when flipped back to the top where we can see the 12va 12vb and 12vc the last thing to point out is the quality of the filtering caps for dc output we see these brown electrolytics which are made by genson and these green ones which are from samsung not sure on their pronunciation there these are in our gf series neither of these show up anywhere near the top of various capacitor tier lists on the internet so with some components like our toshiba mosfets being reputable and other parts like these caps being less so we moved on to testing to see how it actually performed so here again is our delphi our dell g5 power supply and these are the cables that come out of it and this is one of the connectors that was on the end of it this is actually the motherboard connector it looks a lot like a pci express connector but it is keyed differently and unfortunately it does not follow the atx 12vo spec either so we got kind of like this weird connector and we wanted to connect this power supply to our sm8800 over here but the sm8800 has a standard atx set of inputs on it so we had to find some way to make this thing work with this and it's not keyed correctly to fit into a pci express connector or an eps 12-volt connector or this atx 24-pin connector so we had to find some way to take these wires that are in this thing and make it work with our power supply tester so what we did is we just simply used this little tool right here it's basically a cable modding kit pick and you can stick this guy into these guys and into these pins in the front and it will release the pins so you can pull them out the back so we just mapped the correct wires to the correct positions on an atx 24 pin connector these purple ones are 12 volt so we just put them in 12 volt slots on the 24 pin connector and the black ones are ground so we put them in ground spots on the connector and then we have the power ok and the ps on wires as well that's your blue and your gray so we just fit those into the correct locations on an atx 24 pin connect that we already had and then that was able to plug directly into our sm 8800 and then we were able to fully control our testing no problem back to you steve back over to the testing we should talk more about what the word rail means specifically with power supplies a rail is a dc output of a power supply that provides a specific voltage to the pc you can envision this as a section or a zone of the power supply circuitry that's built solely for the purpose of outputting the given voltage an easy to relate example is the rails in a multi-rail psu in these power supplies there are separate circuits for plus 12 volts dc plus 5 volts dc plus 3.3 plus 5 volts standby and minus 12 volts dc the outputs of these are then routed to different connectors as needed sata connectors are good for demonstrating how a rail is different from a connector each sata connector needs a plus 12 volts dc a plus 5 and a plus 3.3 volt dc and you can see that clearly if you look at a wiring diagram of a sata connector for example on our mod mats available on store.camerasex.net so it's a single power connector that draws from three different rails in some power supplies the 12-volt signal can be separated into more than one output circuit when this is done the power supply is said to have multiple 12-volt rails or to be multi-rail there may be a 12v1 and a 12v2 or 12va and 12vb how this is implemented in the circuitry also varies from manufacturer to manufacturer and on the dell psu the label on the side gives us a clue it claims that there are three 12-volt rails a b and c and our ocp testing verified that there were separate ocp trigger points for each 12-volt rail the bottom of the pcb shows that each of the 12 volt outputs has a separate current limiting circuit for protection purposes this means that the power supply is limited when comparing it to a more common multi-rail power supply with a single 12-volt rail so it can never supply full power to one 12-volt rail in supplies with single 12 volt rails the current limit typically aligns with the power supply capacity this allows us to properly supply hddt components that require more power especially if bursted with dell solution unfortunately you'll never really be able to upgrade the gpu although it's a 500 watt power supply and the cpu is only a 65 watt part so there's a lot of room there we're never going to get 500 watts out of this power supply in this configuration we're effectively running a 208 watt power supply instead we'll use 65 on the cpu unless upgraded and maximally 130 watts on a cpu in this socket with this bios so that means we only ever have 216 watts for the gpu so 500 watts is sort of a lie on this particular power supply but this isn't unique to dell it will never be in a situation with the stock system and the dell bios where it can actually draw anywhere close to that let's get into testing efficiency is one way to measure the quality of a power supply and we tested the l500 epmo at several load levels to determine how efficient it is we started our testing at two percent because as of 2020 low power requirements have been adopted in both the multi-rail and the 12v desktop power supplies intel's 12vo power supply design guide calls for 72 efficiency at 2 percent the dell power supply while not officially part of any form factor or claiming to be atx 2.53 certified comes really close to meeting the standard at 69.1 percent at 10 load the unit is at 89.1 percent efficiency which almost reaches the 80 plus titanium standard of 90 percent this is actually outstanding for an oem psu 20 load is where 80 plus through 80 plus platinum start their certification measurements and once again this power supply does surprisingly well meeting the 80 plus titanium standards of 92 percent efficiency with a pfc or power factor correction of greater than or equal to 0.95 the stats for the device under test were 92.2 percent efficiency with a pfc of 0.986 summing up the 80 plus numbers it doesn't quite make titanium at 50 load falling short at 92.7 in our testing with a 94 requirement but it regains the titanium level at 100 load squeaking in at 90.1 percent with 90 required we also performed testing at 30 load resulting in our peak efficiency of 92.9 percent 70 load coming in at 91.8 percent and then 90 load which yielded a 90.7 percent efficiency for an oem power supply it's surprising in its efficiency dell has a public report validating this power supply and several others identifying the l500 epmo as an official 80 plus certified product despite its lack of any 80 plus branding in our testing it missed the 80 plus titanium rating by a mere 1.3 percentage points and that puts it solidly in the 80 plus platinum category to look at the efficiency from a different perspective we also plotted the input versus output power for the dell l 500 epm this chart helps visualize the efficiency curve with real numbers the numbers reflect the ac power in versus the dc out on the power supply dc out is what your pc's components are consuming while the input is what's coming from the wall at the bottom left of the graph the difference is small because the power drop is small the ac input at two percent was 14.03 watts compared to 9.7 consumed by the g5 the gap continues to widen as power draw continues to increase ultimately resulting in an over 80 watt delta at 120 percent where the ac input was about 675 watts compared to the dc output about 594 watts voltage ripple is one of the most important metrics for determining the quality of power delivered to a system a power supply can be efficient while still having bad ripple characteristics which could introduce system instability or reduce overclocking performance we're using a rigel 1054 z oscilloscope connected to the sm 8800 via bnc for this part of testing measuring vpp for ripple the 12vo design guide specifies a maximum of 120 millivolts peak to peak the best power supplies we've tested though have been around 30 millivolts peak to peak at 100 load with the absolute best on the market like the 500 power supplies nearing 10 to 15 millivolts of ripple at our lowest load of 2 percent the g5 psu had an average voltage ripple on the 12 volt rails about 33 millivolts it was up to 48 by the time we tested 20 load and scaled higher as we continued to increase the load on the psu at 50 the peak-to-peak measurement was 52 millivolts and it hit 60 millivolts under 100 load the ripple continued to increase as we pushed to 110 120 load but those are beyond the specifications of the psu and so we'll cut dell and light on some slack there with 52 millivolts at 50 percent and 60 volts at 100 this power supply is simply average it isn't amazing but it's not offensive so it's okay for overall ripple on 12 volts especially for the type of system it's going in another quality metric for power supplies is voltage regulation or how close to the listed voltage is a power supply can keep its outputs in this case we're focused on 12 volts so using the 12 vo design guide as the minimum standard we're looking for a plus or minus 5 percent from the nominal voltage of 12 that comes out to 0.6 volts in either direction so 11.4 to 12.6 that's a large area of operation but we do have to consider that the intel guys are written for everything that includes email checking and word processing workstations to high on desktops there's a difference in the recommended specifications as well and what's actually desired the best power supplies have plus or minus one percent or less voltage variation so we're looking for somewhere in between the dell l 500 epm worked out to about 1.5 percent at worst on its second atx 12 volt connector and 1.3 percent at best on its first atx 12-volt connector so we'll give it a good rating in this statistical category we did limited protection testing on the g5 psu as well particularly over current protection or ocp and over power protection or opp lidon's label says that this power supply should be able to take at least 18 amps on each 12 volt rail so we set each 12 volt rail to hit 18 amps we then switched our sm 8800 into amps mode and increased the current until we hit a breaking point for the dell 500 watt unit that breaking point was approximately 22.5 amps on the atx 12 volt connectors or 19.8 amps on the motherboard connector and 19.5 amps on the pcie 6-pin connector the power supply triggered over current protection and safely shut down on each of the rails the specific shutdown percentages were 125 on 12 va 110 on 12 vb 108 percent on 12vc we also performed over power protection testing and the power supply was able to run at 695 watts before shutting down that was when pushed to 696 watts current levels were 18.9 amps on 12v and c and 10.4 amps on 12va1 and a2 this equates to a 140 opp trigger point which is high when compared to most power supplies but it works consistently and quickly ideally however opp should trigger much sooner than that because a higher number here isn't better it's not a good thing if a power supply especially of this quality is allowed to go to 140 power ideally opp should trigger sooner to reduce risk of catastrophic failures and high power high heat failures that can cause damage elsewhere in the system so that's it for the dell power supply review it's actually good it's not great there are downsides the biggest one being the 12 volt rail split that we talked about earlier although it can you can go over power quite a bit this however can be a downside as well dell we would like to see bring down the overpower protection a little bit lower because as your opp goes higher there's more of a risk of a bigger failure when it eventually does fail if opp doesn't trip or if it's been tripped before and uh at some point you just blow stuff up but overall the biggest drawback is definitely being proprietary the motherboard connector is not anything you can use in another box other than maybe another dell box and it's unfortunate because it turns this into e-waste when it actually is a reasonable power supply that if you bought this computer and in a couple years you wanted to pull the power supply out because it's still alive when the other parts are obsolete and you wanted to use it for something else you just can't the positives for this thing were very positive it's highly efficient it was just short of titanium in a couple of categories which is crazy good the output that dell is getting or light on is getting for the components they've chosen is also very good they're not great components but the performance and the efficiency overall again solid so oh and power factor is looking good too so biggest downsides proprietary and contributes to e-waste but the upsides are great upside so dell you've got something you can you can get some goodwill with let's let's make these not proprietary at least do tfx or something that could be used in like a generic school uh set top computer or something like that but that's it for this one hopefully the power supply review is interesting for you all and obviously let us know what you think what you'd like to see in future ones we'll be working on more of these and patrick stone will be heading up a lot of that stuff so check back for more subscribe for more as always you can go to store.gamersexes.net or patreon.comgamersnexus if you would like to help us in funding these extended testing efforts and our uh equipment use you can grab one of the mousepads as an example we have the new component design in blue and black and the gpu design and black and red and otherwise subscribe for more we'll see you all next timewe're doing power supply testing so this will be a pretty fun video for all the problems with the dell g55000 like walmart system that it built a couple years ago there's actually one element of it that you might not expect would be pretty good and that's this this plain stamped steel metal box odd form factor power supply it's not quite tfx it's definitely not atx it's not even quite atx 12vo despite only having 12 volts but in our testing this power supply did pretty well so we're going to be looking at the dell power supply from the g5000 but because we know that no one's actually buying this thing standalone because it's not sold that way we're planning to use this video as a means to educate a little bit on power supplies and how power supplies work and also provide a look at power supply testing and what power supply testing looks like the way we're doing it right now before that this video is brought to you by evga's new keyboards evj's new z20 and z15 rgb optical mechanical gaming keyboards have abundant rgb leds and programmable macro keys on the left side of the keyboard they also have a sensor to detect and turn on the leds when you're in front of the keyboard and turn them off when distant offering a unique feature for keywords the keyboard claims a 0.5 millisecond response time and 100 million keystroke lifespan learn more at the link in the description below so we've only done one full power supply review in the past and we have all the equipment for power supply testing we're using a sun moon sm 8800 we have load generators and monitors oscilloscopes all the stuff you would need for power supply reviews and we're starting to do more with it lately this was an excellent opportunity for us to try our hand at doing more serious power supply reviews once again using something that would be fun a little bit different and serve as a great means for educating on the basics again of power supply so that's why we've chosen this one uh and we thought it'd be fun to see if dell pulled anything off well with the g5 5000 since clearly nothing else did well in our review of it and this is the one aspect that dell has has done reasonably well here we have some other power supply stuff in the works right now too we've been working slowly on a gigabyte piece that's currently going through endurance testing that's why we're delayed while we wait for the endurance testing to sort of finish as we get into this review a quick note so although we have all the equipment for power supply testing we're still figuring out sort of how to best present the data and how to put it all together what tests to run things like that so this isn't representative of what we're going to be doing for all of them or for gigabytes uh we're still figuring it out still playing around with it so give us a little bit of time on really refining our power supply reviews we need to learn a lot as well but uh you'll be there learning with us as we progress through power supply reviews and we're looking forward to it because the new component review category for us and it's fun and interesting uh let's get started with this dell thing so this is not a standard form factor it's a dell special as with everything else in this g5 5000 and we checked the intel multi-rail desktop power supply design guide the intel atx 12vo desktop design guide and we even looked through the tfx form factor design guides listed in section 14 of both documents and we couldn't find anything that exactly described this box it's a special one it's it's proprietary for sure tfx in its section of the design documents describes a specific cooling solution and specific sizing this power supply is a little bit too long so that eliminates it from the sizing category it has a different cooling solution so this is not tfx but it looks close to it from the outside now the biggest downside with this power supply that we noted when we reviewed the g55000 was its odd selection of cables so because it is 12 volts only but not 12vo what we end up with is a and an odd solution for motherboard power so there's actually no 24 pin atx uh connector this is something we've rigged up for our own testing that patrick stone will describe later in this piece he'll talk about the pin outs and why we wired a custom cable for testing this power supply instead it connects a six pin to the motherboard 12 vo is 10 pins so it's not that and then for eps 12 volt we have normal four pin headers and then for the pcie we have the standard connectors for those but there's no sata because there's no 5 or 3.3 volts and so we're left with an odd solution and that unfortunately makes it not usable in other systems than this dell box or other boxes that happen to have a really bizarre 6 pin motherboard power connector but you could adapt it like we've done here except no one's going to do that so hence the using this as an educational piece more than anything else the labels on the housing and the interior of the power supply and the pcb make it clear that this is manufactured by light on for dell with the model number l 500 epm dash double zero its label is that it can output a combined 500 watts across four physical outputs that's one pcie six or eight pin daisy chain connector one completely proprietary six pin motherboard connection housed in a uniquely keyed 2x3 molex minifit junior connector and two 2x2 4-pin atx 12-volt connectors this was so close to being a standard set of atx 12vo connectors that it's mind-boggling as to why dell would go out of its way to ask light on to make something unique dell's biggest contribution to this design was ensuring that it's destined for a landfill once the computer has served its life and that's really unfortunate because as you'll see in our charts today the power supply as a power supply did pretty well so it'd be great to not have one system only that this works in because it could be applied to other systems and would power them efficiently if only dell decided to make that possible the wires on the specialized motherboard connector are two grounds there's two 12 volts a ps on and power okay the motherboard connector in the atx 12vo standard adds only one more signal 12 vsp or 12 volt standby the other three pins of the 12vo motherboard connector are a reserved location sometimes empty an additional 12 volts and a ground we get that it might cost more to implement the new 12 volt standby functionality and maybe that's why dell chose to go this no it's it's definitely why dell chose to go this route but 12 volt standby is not brand new and there are parts that dell could purchase from suppliers without having to design anything new so now that we've gone through some of the basics of the box i'm going to pass it off to patrick stone who's been working on the power supply testing for this and the gigabyte piece and all the other stuff we're doing with power supplies lately he is going to describe to you the basics of how power supply works using this as a vehicle for it and he'll also go through some of the internal components we'll put some diagrams on the screen with those component names as we get through them and then we'll talk about the performance and the efficiency and all the 80 plus certification sort of alignment by the dell power thanks steve thanks steve the primary function of a power supply is to take the ac from your wall and convert it into dc that your pc can actually use and that all starts over here on the ac plug-in side and you can see we've got the one connector down here by itself that's your ground connection and then the other two terminals that are in parallel with one another those carry the ac voltage whether that's 115 or 230 depending upon where you live the internal components in this housing take the 115 or 230 volts ac and convert it to 12 volt dc and the wires that carry the 12 volt dc on this particular power supply are two for the cpu one for the gpu and one for the motherboard each of these connectors carries both 12 volt and ground with the motherboard also having connection for two power sensing wires this motherboard connector might look a little bit unusual but that's because we had to alter it for testing we'll talk more about that later now let's get this thing open to see what's inside so we've already removed the screws from here here and here so we should be able to just slide this cover off to get access to the pcb just a little uh there we go a little click action then additionally we've already unscrewed the screws in the four corners of the pcb so all we got to do now is remove these wires which we've also already unplugged to make this disassembly easier each of these wires as we're pulling this pcb out of here goes to different stuff so like this one over here goes to this 40 millimeter cooling fan this one right here goes to a status led that shows that the power supplies on or not and this one is our main ac connector all right we'll start with that ac power connector plugs in the power runs through protection and filtering circuits gets rectified from ac to dc at this tower hits a bit more protection then goes off to the heatsink tower for active power factor correction or apfc comes back here and runs through this inductor for some current limiting and then it goes to this bulk storage cap for some smoothing it then returns to the tower where the power gets pulse width modulated into an ac rectangular waveform from there it flows to the transformer to be stepped down from a high ac voltage to a lower ac voltage that is close to the level that we need for our output then it goes to what looks like blank fins but if we flip to the bottom we find a set of mosfets that rectify our lower voltage rectangular ac waveform back to the dc that we need for output we then hit some protection circuitry here and then some filtering capacitors here and finally end up at the 12 volt dc output and now we're back outside the box let's go back to the beginning and look more closely at some of the key components the fuse and mov or metal oxide varistor work together as current and voltage protections respectively current here voltage here x caps these boxes and y caps these little blue guys work along with these large chokes to filter out noise and interference power isn't smooth and clean when it's delivering the power company and our cpus gps and motherboards want clean power so this is where that initial cleanup is done the high voltage ac to dc conversion happens inside these gbu808s which are eight amp 800 volt bridge rectifiers the output of that runs into an interesting component combo an ntc thermistor and a relay the ntc thermistor limits inrush current but after initial startup there's less risk of inrush so that thermistor isn't needed the relay allows the psu to bypass the thermistor which then increases the psu's overall efficiency the apfc is carried out by a set of toshiba mosfets and a controller on this board here once our power factor is taken care of we hit the large inductor and capacitor the cap necessitates the inductor because caps draw in current so this inductor is there to limit the current inflow rate then we head back to the cooling tower where another set of toshiba mosfets exactly the same as the apfc ones are controlled by a pwm chip to change our dc signal back to ac so that it can be used as the input for the large transformer we already stated the transformer steps the voltage down but it also performs another function isolating the primary side from the secondary side thanks to electromagnetism if you're just learning about psus it's a good idea to learn to identify this component because it's a good dmarc point for separating the two sides of the psu going toward the dc output we have to flip the pcb over again to see the mosfets that rectify ac back to dc for the final output voltage it's interesting to see how the output of that circuit is broken into three paths or rails that turn out to be protection circuits each one of these goes to 12 volt a or b or c these through-hole terminals which is more obvious when flipped back to the top where we can see the 12va 12vb and 12vc the last thing to point out is the quality of the filtering caps for dc output we see these brown electrolytics which are made by genson and these green ones which are from samsung not sure on their pronunciation there these are in our gf series neither of these show up anywhere near the top of various capacitor tier lists on the internet so with some components like our toshiba mosfets being reputable and other parts like these caps being less so we moved on to testing to see how it actually performed so here again is our delphi our dell g5 power supply and these are the cables that come out of it and this is one of the connectors that was on the end of it this is actually the motherboard connector it looks a lot like a pci express connector but it is keyed differently and unfortunately it does not follow the atx 12vo spec either so we got kind of like this weird connector and we wanted to connect this power supply to our sm8800 over here but the sm8800 has a standard atx set of inputs on it so we had to find some way to make this thing work with this and it's not keyed correctly to fit into a pci express connector or an eps 12-volt connector or this atx 24-pin connector so we had to find some way to take these wires that are in this thing and make it work with our power supply tester so what we did is we just simply used this little tool right here it's basically a cable modding kit pick and you can stick this guy into these guys and into these pins in the front and it will release the pins so you can pull them out the back so we just mapped the correct wires to the correct positions on an atx 24 pin connector these purple ones are 12 volt so we just put them in 12 volt slots on the 24 pin connector and the black ones are ground so we put them in ground spots on the connector and then we have the power ok and the ps on wires as well that's your blue and your gray so we just fit those into the correct locations on an atx 24 pin connect that we already had and then that was able to plug directly into our sm 8800 and then we were able to fully control our testing no problem back to you steve back over to the testing we should talk more about what the word rail means specifically with power supplies a rail is a dc output of a power supply that provides a specific voltage to the pc you can envision this as a section or a zone of the power supply circuitry that's built solely for the purpose of outputting the given voltage an easy to relate example is the rails in a multi-rail psu in these power supplies there are separate circuits for plus 12 volts dc plus 5 volts dc plus 3.3 plus 5 volts standby and minus 12 volts dc the outputs of these are then routed to different connectors as needed sata connectors are good for demonstrating how a rail is different from a connector each sata connector needs a plus 12 volts dc a plus 5 and a plus 3.3 volt dc and you can see that clearly if you look at a wiring diagram of a sata connector for example on our mod mats available on store.camerasex.net so it's a single power connector that draws from three different rails in some power supplies the 12-volt signal can be separated into more than one output circuit when this is done the power supply is said to have multiple 12-volt rails or to be multi-rail there may be a 12v1 and a 12v2 or 12va and 12vb how this is implemented in the circuitry also varies from manufacturer to manufacturer and on the dell psu the label on the side gives us a clue it claims that there are three 12-volt rails a b and c and our ocp testing verified that there were separate ocp trigger points for each 12-volt rail the bottom of the pcb shows that each of the 12 volt outputs has a separate current limiting circuit for protection purposes this means that the power supply is limited when comparing it to a more common multi-rail power supply with a single 12-volt rail so it can never supply full power to one 12-volt rail in supplies with single 12 volt rails the current limit typically aligns with the power supply capacity this allows us to properly supply hddt components that require more power especially if bursted with dell solution unfortunately you'll never really be able to upgrade the gpu although it's a 500 watt power supply and the cpu is only a 65 watt part so there's a lot of room there we're never going to get 500 watts out of this power supply in this configuration we're effectively running a 208 watt power supply instead we'll use 65 on the cpu unless upgraded and maximally 130 watts on a cpu in this socket with this bios so that means we only ever have 216 watts for the gpu so 500 watts is sort of a lie on this particular power supply but this isn't unique to dell it will never be in a situation with the stock system and the dell bios where it can actually draw anywhere close to that let's get into testing efficiency is one way to measure the quality of a power supply and we tested the l500 epmo at several load levels to determine how efficient it is we started our testing at two percent because as of 2020 low power requirements have been adopted in both the multi-rail and the 12v desktop power supplies intel's 12vo power supply design guide calls for 72 efficiency at 2 percent the dell power supply while not officially part of any form factor or claiming to be atx 2.53 certified comes really close to meeting the standard at 69.1 percent at 10 load the unit is at 89.1 percent efficiency which almost reaches the 80 plus titanium standard of 90 percent this is actually outstanding for an oem psu 20 load is where 80 plus through 80 plus platinum start their certification measurements and once again this power supply does surprisingly well meeting the 80 plus titanium standards of 92 percent efficiency with a pfc or power factor correction of greater than or equal to 0.95 the stats for the device under test were 92.2 percent efficiency with a pfc of 0.986 summing up the 80 plus numbers it doesn't quite make titanium at 50 load falling short at 92.7 in our testing with a 94 requirement but it regains the titanium level at 100 load squeaking in at 90.1 percent with 90 required we also performed testing at 30 load resulting in our peak efficiency of 92.9 percent 70 load coming in at 91.8 percent and then 90 load which yielded a 90.7 percent efficiency for an oem power supply it's surprising in its efficiency dell has a public report validating this power supply and several others identifying the l500 epmo as an official 80 plus certified product despite its lack of any 80 plus branding in our testing it missed the 80 plus titanium rating by a mere 1.3 percentage points and that puts it solidly in the 80 plus platinum category to look at the efficiency from a different perspective we also plotted the input versus output power for the dell l 500 epm this chart helps visualize the efficiency curve with real numbers the numbers reflect the ac power in versus the dc out on the power supply dc out is what your pc's components are consuming while the input is what's coming from the wall at the bottom left of the graph the difference is small because the power drop is small the ac input at two percent was 14.03 watts compared to 9.7 consumed by the g5 the gap continues to widen as power draw continues to increase ultimately resulting in an over 80 watt delta at 120 percent where the ac input was about 675 watts compared to the dc output about 594 watts voltage ripple is one of the most important metrics for determining the quality of power delivered to a system a power supply can be efficient while still having bad ripple characteristics which could introduce system instability or reduce overclocking performance we're using a rigel 1054 z oscilloscope connected to the sm 8800 via bnc for this part of testing measuring vpp for ripple the 12vo design guide specifies a maximum of 120 millivolts peak to peak the best power supplies we've tested though have been around 30 millivolts peak to peak at 100 load with the absolute best on the market like the 500 power supplies nearing 10 to 15 millivolts of ripple at our lowest load of 2 percent the g5 psu had an average voltage ripple on the 12 volt rails about 33 millivolts it was up to 48 by the time we tested 20 load and scaled higher as we continued to increase the load on the psu at 50 the peak-to-peak measurement was 52 millivolts and it hit 60 millivolts under 100 load the ripple continued to increase as we pushed to 110 120 load but those are beyond the specifications of the psu and so we'll cut dell and light on some slack there with 52 millivolts at 50 percent and 60 volts at 100 this power supply is simply average it isn't amazing but it's not offensive so it's okay for overall ripple on 12 volts especially for the type of system it's going in another quality metric for power supplies is voltage regulation or how close to the listed voltage is a power supply can keep its outputs in this case we're focused on 12 volts so using the 12 vo design guide as the minimum standard we're looking for a plus or minus 5 percent from the nominal voltage of 12 that comes out to 0.6 volts in either direction so 11.4 to 12.6 that's a large area of operation but we do have to consider that the intel guys are written for everything that includes email checking and word processing workstations to high on desktops there's a difference in the recommended specifications as well and what's actually desired the best power supplies have plus or minus one percent or less voltage variation so we're looking for somewhere in between the dell l 500 epm worked out to about 1.5 percent at worst on its second atx 12 volt connector and 1.3 percent at best on its first atx 12-volt connector so we'll give it a good rating in this statistical category we did limited protection testing on the g5 psu as well particularly over current protection or ocp and over power protection or opp lidon's label says that this power supply should be able to take at least 18 amps on each 12 volt rail so we set each 12 volt rail to hit 18 amps we then switched our sm 8800 into amps mode and increased the current until we hit a breaking point for the dell 500 watt unit that breaking point was approximately 22.5 amps on the atx 12 volt connectors or 19.8 amps on the motherboard connector and 19.5 amps on the pcie 6-pin connector the power supply triggered over current protection and safely shut down on each of the rails the specific shutdown percentages were 125 on 12 va 110 on 12 vb 108 percent on 12vc we also performed over power protection testing and the power supply was able to run at 695 watts before shutting down that was when pushed to 696 watts current levels were 18.9 amps on 12v and c and 10.4 amps on 12va1 and a2 this equates to a 140 opp trigger point which is high when compared to most power supplies but it works consistently and quickly ideally however opp should trigger much sooner than that because a higher number here isn't better it's not a good thing if a power supply especially of this quality is allowed to go to 140 power ideally opp should trigger sooner to reduce risk of catastrophic failures and high power high heat failures that can cause damage elsewhere in the system so that's it for the dell power supply review it's actually good it's not great there are downsides the biggest one being the 12 volt rail split that we talked about earlier although it can you can go over power quite a bit this however can be a downside as well dell we would like to see bring down the overpower protection a little bit lower because as your opp goes higher there's more of a risk of a bigger failure when it eventually does fail if opp doesn't trip or if it's been tripped before and uh at some point you just blow stuff up but overall the biggest drawback is definitely being proprietary the motherboard connector is not anything you can use in another box other than maybe another dell box and it's unfortunate because it turns this into e-waste when it actually is a reasonable power supply that if you bought this computer and in a couple years you wanted to pull the power supply out because it's still alive when the other parts are obsolete and you wanted to use it for something else you just can't the positives for this thing were very positive it's highly efficient it was just short of titanium in a couple of categories which is crazy good the output that dell is getting or light on is getting for the components they've chosen is also very good they're not great components but the performance and the efficiency overall again solid so oh and power factor is looking good too so biggest downsides proprietary and contributes to e-waste but the upsides are great upside so dell you've got something you can you can get some goodwill with let's let's make these not proprietary at least do tfx or something that could be used in like a generic school uh set top computer or something like that but that's it for this one hopefully the power supply review is interesting for you all and obviously let us know what you think what you'd like to see in future ones we'll be working on more of these and patrick stone will be heading up a lot of that stuff so check back for more subscribe for more as always you can go to store.gamersexes.net or patreon.comgamersnexus if you would like to help us in funding these extended testing efforts and our uh equipment use you can grab one of the mousepads as an example we have the new component design in blue and black and the gpu design and black and red and otherwise subscribe for more we'll see you all next time\n"