The Core Voltage VRM: A Detailed Analysis

Let's move over to the other major VRM on this card and that's the memory voltage VRM right here. This is a two-phase VRM we have two chokes here, uh it's controlled by the UP 1665, uh this is a two-phase voltage controller with integrated drivers. So basically there's no driver ICs anywhere around this area because this can actually drive the mosfets directly.

Speaking of the mosfets, these are Fairchild power trench power stages, so these are not regular mosfets. These are high side fat and a low side fat integrated into one. I see so each of these is actually enough to make up its own single phase, and there's two of them in each phase because Gigabyte wanted even more current capability, so they put two of them in parallel to get more current throughput. The end result of this is that each of these has a 13 amp high side and that's a continuous rating. So obviously in a VRM you can expect it to do quite a bit more than that.

The Continuous rating is still very conservative because the high side mosfet is basically being turned on and off hundreds of thousands of times a second, it doesn't stay on continuously so you can actually expect it to do quite a bit more than the 13 amps continuous rating even in this terribly cooled scenario that it's in. The high the low side fat is 23 amps, uh continuous and that rating is actually realistically what it will actually be able to handle in this application because the lows side fat is turned on for most of the time when in AVRM.

So we have 13 amps well not even 13 let's say you know 15 or 16 amps per per IC in each phase, so that gives us about 30 amps for each given phase two phases total. You have 60 amps if you don't go by the absolute worst case scenario and if you go by worst case possible scenario then it's 50-2 amps because that's the high side mosfet's continuous rating for no proper cooling scenarios.

This is again ridiculously overkill, the GDDR5X on a 1080 pulls around 30 Watts which with the voltage it runs at works out to around 22 amps. So we have a 52 amp memory VRM here, and Gigabyte went ridiculously over and I suspect it's again because there's no proper air flow in this area due to the lack of a fan. So yeah does mean that if you actually try to get some air flow into the shroud of the card this VRM is just going to be amazing like perform amazingly and in its stock configuration it's also perfectly good.

Because Gigabyte really did go insanely overkill on everything just to make sure that it can function in the less than optimal cooling environment that they've decided to go with on the Water Force, whereas the Gaming Extreme, the while know the extreme gaming so that's the air cooled version of this card. That one would actually have a heat sink here with proper air flow over the entire VRM section.

So that's that for the PCB breakdown.

"WEBVTTKind: captionsLanguage: enguys buildzoid here and today we're going to be taking a look at another GTX 1080 PCB this time the gigabyte extreme uh water Force card this also shares its PCB with the extreme gaming uh which is the aircooled version of this uh same card uh if you would like to see the re full review of the card you can find a link to that in the description down below and with that out of the way let's get to actually taking a look at this PCB first things first we have the core voltage vrm right here and that provides power to the GPU core uh down here we have the 1vt PLL voltage this is a extra voltage that is required to make the GPU core work but it's not really an important vrm it's very low power it doesn't have any impact on overclocking and it you know isn't impacted in O by overclocking and any in any way either and so it doesn't really matter and you know we're not going to actually cover that one in detail over here we have the memory vrm that provides power to the gddr5x uh chips surrounding the GPU core and in this area somewhere there is the 1.8 volt rail which also goes to the gddr5x chips and basically um it's again a low power vrm and it's basically just necessary for the gddr5x chips to work they take the bulk of their power from this vrm over there um so with all of the vrms uh identified let's actually take a closer look at what they're made up of first of all the core voltage is a 12-phase vrm we have 1 2 3 4 5 6 7 8 9 10 11 12 uh inductors or chokes whichever you prefer to call them and each of these has its own Dr Moss power module so each of these has you know a power module unfortunately uh the thermal pads cover uh some of them but you know if those weren't there you could see that there's actually 12 of these so this is a real real 12 phase design uh these Dr Moss power modules these are fdm uh 6823 C's from Fairchild semiconductor these are rated to do uh 50 amps at 300 khz or 45 amps at 1 mahz um so know they're plenty powerful and with you know this 12 phase vrm and one of these per phase you get around 540 to 600 amps of current capability uh through this vrm here uh obviously if you've watched my uh previous uh previous PCB breakdowns you would know that the that getting a face count above uh eight phases uh requires some extra uh extra circuitry um and this being a 12 phase it needs to use doublers or or at least doublers or quadrupler to actually achieve the 12 pH uh 12 phases so this is done by these three ic's on the PCB these are up uh 1911 RS each of them takes in a pwm signal from the up 9511 uh located over here so this is the vrm control control chip so that monitors the vrm output voltage power draw and everything for this here vrm and it feeds each of these uh 1911 r p uh 1911 uh R chips uh a pwm signal and also monitors the current readings that are coming out of those and those then take that pwm signal and feed it into four uh four of the uh four of the Dr Moss modules located in the VR RM itself now these chips do have a downside they cut your switching frequency but to 1/4 of what you're uh feeding them so essentially it means that you have less accurate control over each of the phases however gigabyte can actually get around this uh you know downside of using these chips by uh using a really high switching frequency from the N uh 9511 um and the 9511 can provide up to 2 MHz switching frequency so you know that's basically 2 million uh updates for you know you know uh mosat uh like phase updates per second and basically when that goes to the quadrupler that means each phase can be updated as many as 500,000 times a second so it can adjust the current through that phase that many times each second and that means that as long as gigabyte uses a reasonable switching frequency on the uh you know the up 9511 the vrm actually runs you know actually relatively clean power uh on par with basically any other GTX 1080 because 200 to 500 khz switching frequency is the usual uh vrm switching frequency that you'll see on most graphics cards and really going above that is generally completely unnecessary um unless you're doing extreme overclocking or something like that and even in those cases it often doesn't really help anything because most vrms can get away with uh can actually do very very clean power at you know 200 or 500 khz already so really running super high frequencies isn't a requirement so the fact that gigabytes using these quadrupler isn't uh isn't a major down side however it is still interesting that they use quadrupler and I'm pretty sure that you know uh and this the reason for that is that quadrupler are relatively expensive and they don't like it doesn't really make sense to use them in many in situations like this where you could have just used six uh pwm signals from the uh from the control chip and then uh use doublers to actually get your 12 phases however I do believe gigabyte opted for the quadrupler because this card has display outputs all the way over here as well as over here and the way these guys work is that there's these switches over here so you have display uh so normally your display signal goes to the back of the card but if you would like to the card will put the signal to towards the back and then this switch will actually send it around to the other end of the card uh and this is for VR so that you can hook up a VR output to to the front panel of your uh you know of your Tower and basically by doing this there's a lot of extra traces that have to go through the PCB and that means there's a lot less uh available space to Route traces for the 12 phas vrm which would normally require a pretty significant amount of phases uh traces coming off of the uh control chip located right there so gigabyte obvious seems to have opted for the quadrupler to minimize the amount of traces coming directly off of the um off of the up9 9511 and tried to spread them out between the quadrupler chips uh around the card so overall the core voltage vrm is perfectly fine ridiculously overkill for a GTX 1080 as I said before uh something around you know between 540 and 600 amps depending on how uh what switching frequency gigabyte opted to to uh feed into the quadrupler and uh the reason for this partially is because this vrm in this uh in the water Force card there's no airflow in this area because there's no fan and there's actually no air flow anywhere on the PCB of the card so all of the cooling of the card is has to be taken care of by just you know uh passive air flow from your case fans or from the fact that hot air rises and everything uh and the then the the bulk of the heat of the card is then taken care of by an AO cooler sitting over the GPU core right here and that AIO cooler has a copper plate that covers all the gddr5x chips so those are well cooled and then there's a heat pipe coming off of an aluminum block that you know is in contact with the uh core voltage vrm right here and that then pipes heat into the copper copper plate that the AIO cooler uses to actually also cool the gddr5x chips so that's how gigabyte basically cools the vrm but because this isn't a particularly efficient way to cool a vrm it does mean that they've probably you know did this ridiculous amount of overs speec on the vrm partially to comp compensate for the fact that the vrm temperatures are going to be less than you know less than optimal they're really going to be quite up there because that one heat pipe having to take all of this heat through an aluminum block and through SE like the thing is like when you're bonding heat sinks together you know you have aluminum block solder copper heat pipe solder copper uh copper cold plate for the water block and that's just a lot of different materials for the heat to transition uh through and that really impedes heat transfer performance that means this vrm even with the heat pipe will be running pretty uh pretty toasty so the ridiculous Overkill rating here uh that's at 25 degrees ambient which is basically assuming that the mosfets are you know capable of being cooled by the uh hot air rises uh uh air flow whereas here in a case the card will most likely be upside down so that's really not going to work that great so the aluminum block uh is there to you know make sure that the uh vrm get gets at least some active cooling but even then it's it's less than optimal so I think this ridiculous like current capability is just basically compensating for the fact that the vrm is going to run really really hot uh because there's really no reason why you would need this on a GTX 1080 uh it won't really help overclocking performance because the card will never ever need this much current but it is you know nice that this vrm is so ridiculously overbuilt because you basically have peace of mind that there is no way you're ever going to have this fail on you assuming that there isn't some manufacturing defect in it um so yeah props to G Gaby on the core voltage vrm so let's move over to the other major uh vrm on this card and that's the memory voltage vrm right here so that feeds the gddr5x chips this is a two-phase vrm we have two chokes here uh it's controlled by the up 1665 uh this is a two-phase voltage controller with integrated drivers so basically there's no driver ic's anywhere uh you know around this area because this can actually drive the uh mosfets directly and speaking of the mosfets these are uh Fairchild power trench power stages so these are not regular mosfets these are a high side fat and a lows side fat integrated into one I see so each of these is actually enough to make up its you know a single phase and there's two of them in each phase because gigabyte wanted even more current capability so they put two of them in parallel to get more current throughput um the end result of this is that each of these has a 13 amp uh high side and that's a continuous rating so obviously in avrm you can expect it to do quite a bit more than that and that's a 25 degree ambient rating so you know the uh passively cooled no heat sink no air no proper air flow other than other than just convection so uh that you know that rating is most relevant here because uh there is no active air flow over this this part of the vrm and uh it's going to be running pretty hot uh just because of that so I'm going to go with that rating but still The Continuous rating is still very very conservative because the high side moset is basically being turned on and off hundreds of thousands of times a second it doesn't stay on uh continuously so you can actually expect it to do quite a bit more than the 13 amps uh continuous rating even in this uh terribly cooled scenario that it's in um the high the low side fat is 23 amps uh continuous and that rating is actually realistically what it will actually be able to handle uh in this application because the uh lows side fat is turned on for most uh most of the time when in AVR M so that one spends a lot of its time turned on uh so you know we have 13 amps uh well not even 13 let's say you know 15 or 16 amps per per IC in each phase so that gives us about 30 amps for each given phase two phases total you have 60 amps uh you know if you don't go by the absolute worst case scenario and if you go by worst case possible scenario then it's 50 2 amps because that's the uh high side mosfet's continuous rating for no proper cooling scenarios um and this is again ridiculously Overkill the gddr5x um on a 1080 pulls around 30 Watts which with the voltage it runs at works out to around 22 amps so you know we have a we have a 52 amp memory vrm here so gigabyte went ridiculously over and I suspect it's again because there's no proper airf flow in this area due to the lack of the fan so yeah uh does mean that if you actually try to get some air flow into the shroud of the card this vrm is just going to be amaz like perform amazingly and in its stock configuration it's also perfectly good because gigabyte really did go insanely overkill on everything just to make sure that it can uh function in the less than optimal cooling environment that they've uh decided to go with on the water Force um whereas the gaming extreme the while know the extreme gaming so that's the air cooled version of this card that one would actually have a heat sink here with proper air flow over the entire vrm section so that one would actually arguably probably be a you know have better uh vrm capabilities not that it really matters CU this is a GTX 1080 and even in these less than sub you know in these complete suboptimal cooling scenarios the vrm setup that gigabyte has opted for is so ridiculously overkilled that it really doesn't matter they're like you're not going to see a GTX 1080 use anywhere near the full capacity of this vrm I'll be surpris like not even 50% of the capacity of this vrm will ever really be used so yeah very nice uh very nice PCD from gigabyte here and props to them for Designing such a ridic ridiculous monstrosity if you think about it um so that's that for the PCB breakdown uh like the video if you liked it subscribe to the channel if you haven't subscribed yet and do consider uh you know donating to uh Gamers Nexus on patreon so we can keep bringing you more content in the future thank you for watching and see you next timeguys buildzoid here and today we're going to be taking a look at another GTX 1080 PCB this time the gigabyte extreme uh water Force card this also shares its PCB with the extreme gaming uh which is the aircooled version of this uh same card uh if you would like to see the re full review of the card you can find a link to that in the description down below and with that out of the way let's get to actually taking a look at this PCB first things first we have the core voltage vrm right here and that provides power to the GPU core uh down here we have the 1vt PLL voltage this is a extra voltage that is required to make the GPU core work but it's not really an important vrm it's very low power it doesn't have any impact on overclocking and it you know isn't impacted in O by overclocking and any in any way either and so it doesn't really matter and you know we're not going to actually cover that one in detail over here we have the memory vrm that provides power to the gddr5x uh chips surrounding the GPU core and in this area somewhere there is the 1.8 volt rail which also goes to the gddr5x chips and basically um it's again a low power vrm and it's basically just necessary for the gddr5x chips to work they take the bulk of their power from this vrm over there um so with all of the vrms uh identified let's actually take a closer look at what they're made up of first of all the core voltage is a 12-phase vrm we have 1 2 3 4 5 6 7 8 9 10 11 12 uh inductors or chokes whichever you prefer to call them and each of these has its own Dr Moss power module so each of these has you know a power module unfortunately uh the thermal pads cover uh some of them but you know if those weren't there you could see that there's actually 12 of these so this is a real real 12 phase design uh these Dr Moss power modules these are fdm uh 6823 C's from Fairchild semiconductor these are rated to do uh 50 amps at 300 khz or 45 amps at 1 mahz um so know they're plenty powerful and with you know this 12 phase vrm and one of these per phase you get around 540 to 600 amps of current capability uh through this vrm here uh obviously if you've watched my uh previous uh previous PCB breakdowns you would know that the that getting a face count above uh eight phases uh requires some extra uh extra circuitry um and this being a 12 phase it needs to use doublers or or at least doublers or quadrupler to actually achieve the 12 pH uh 12 phases so this is done by these three ic's on the PCB these are up uh 1911 RS each of them takes in a pwm signal from the up 9511 uh located over here so this is the vrm control control chip so that monitors the vrm output voltage power draw and everything for this here vrm and it feeds each of these uh 1911 r p uh 1911 uh R chips uh a pwm signal and also monitors the current readings that are coming out of those and those then take that pwm signal and feed it into four uh four of the uh four of the Dr Moss modules located in the VR RM itself now these chips do have a downside they cut your switching frequency but to 1/4 of what you're uh feeding them so essentially it means that you have less accurate control over each of the phases however gigabyte can actually get around this uh you know downside of using these chips by uh using a really high switching frequency from the N uh 9511 um and the 9511 can provide up to 2 MHz switching frequency so you know that's basically 2 million uh updates for you know you know uh mosat uh like phase updates per second and basically when that goes to the quadrupler that means each phase can be updated as many as 500,000 times a second so it can adjust the current through that phase that many times each second and that means that as long as gigabyte uses a reasonable switching frequency on the uh you know the up 9511 the vrm actually runs you know actually relatively clean power uh on par with basically any other GTX 1080 because 200 to 500 khz switching frequency is the usual uh vrm switching frequency that you'll see on most graphics cards and really going above that is generally completely unnecessary um unless you're doing extreme overclocking or something like that and even in those cases it often doesn't really help anything because most vrms can get away with uh can actually do very very clean power at you know 200 or 500 khz already so really running super high frequencies isn't a requirement so the fact that gigabytes using these quadrupler isn't uh isn't a major down side however it is still interesting that they use quadrupler and I'm pretty sure that you know uh and this the reason for that is that quadrupler are relatively expensive and they don't like it doesn't really make sense to use them in many in situations like this where you could have just used six uh pwm signals from the uh from the control chip and then uh use doublers to actually get your 12 phases however I do believe gigabyte opted for the quadrupler because this card has display outputs all the way over here as well as over here and the way these guys work is that there's these switches over here so you have display uh so normally your display signal goes to the back of the card but if you would like to the card will put the signal to towards the back and then this switch will actually send it around to the other end of the card uh and this is for VR so that you can hook up a VR output to to the front panel of your uh you know of your Tower and basically by doing this there's a lot of extra traces that have to go through the PCB and that means there's a lot less uh available space to Route traces for the 12 phas vrm which would normally require a pretty significant amount of phases uh traces coming off of the uh control chip located right there so gigabyte obvious seems to have opted for the quadrupler to minimize the amount of traces coming directly off of the um off of the up9 9511 and tried to spread them out between the quadrupler chips uh around the card so overall the core voltage vrm is perfectly fine ridiculously overkill for a GTX 1080 as I said before uh something around you know between 540 and 600 amps depending on how uh what switching frequency gigabyte opted to to uh feed into the quadrupler and uh the reason for this partially is because this vrm in this uh in the water Force card there's no airflow in this area because there's no fan and there's actually no air flow anywhere on the PCB of the card so all of the cooling of the card is has to be taken care of by just you know uh passive air flow from your case fans or from the fact that hot air rises and everything uh and the then the the bulk of the heat of the card is then taken care of by an AO cooler sitting over the GPU core right here and that AIO cooler has a copper plate that covers all the gddr5x chips so those are well cooled and then there's a heat pipe coming off of an aluminum block that you know is in contact with the uh core voltage vrm right here and that then pipes heat into the copper copper plate that the AIO cooler uses to actually also cool the gddr5x chips so that's how gigabyte basically cools the vrm but because this isn't a particularly efficient way to cool a vrm it does mean that they've probably you know did this ridiculous amount of overs speec on the vrm partially to comp compensate for the fact that the vrm temperatures are going to be less than you know less than optimal they're really going to be quite up there because that one heat pipe having to take all of this heat through an aluminum block and through SE like the thing is like when you're bonding heat sinks together you know you have aluminum block solder copper heat pipe solder copper uh copper cold plate for the water block and that's just a lot of different materials for the heat to transition uh through and that really impedes heat transfer performance that means this vrm even with the heat pipe will be running pretty uh pretty toasty so the ridiculous Overkill rating here uh that's at 25 degrees ambient which is basically assuming that the mosfets are you know capable of being cooled by the uh hot air rises uh uh air flow whereas here in a case the card will most likely be upside down so that's really not going to work that great so the aluminum block uh is there to you know make sure that the uh vrm get gets at least some active cooling but even then it's it's less than optimal so I think this ridiculous like current capability is just basically compensating for the fact that the vrm is going to run really really hot uh because there's really no reason why you would need this on a GTX 1080 uh it won't really help overclocking performance because the card will never ever need this much current but it is you know nice that this vrm is so ridiculously overbuilt because you basically have peace of mind that there is no way you're ever going to have this fail on you assuming that there isn't some manufacturing defect in it um so yeah props to G Gaby on the core voltage vrm so let's move over to the other major uh vrm on this card and that's the memory voltage vrm right here so that feeds the gddr5x chips this is a two-phase vrm we have two chokes here uh it's controlled by the up 1665 uh this is a two-phase voltage controller with integrated drivers so basically there's no driver ic's anywhere uh you know around this area because this can actually drive the uh mosfets directly and speaking of the mosfets these are uh Fairchild power trench power stages so these are not regular mosfets these are a high side fat and a lows side fat integrated into one I see so each of these is actually enough to make up its you know a single phase and there's two of them in each phase because gigabyte wanted even more current capability so they put two of them in parallel to get more current throughput um the end result of this is that each of these has a 13 amp uh high side and that's a continuous rating so obviously in avrm you can expect it to do quite a bit more than that and that's a 25 degree ambient rating so you know the uh passively cooled no heat sink no air no proper air flow other than other than just convection so uh that you know that rating is most relevant here because uh there is no active air flow over this this part of the vrm and uh it's going to be running pretty hot uh just because of that so I'm going to go with that rating but still The Continuous rating is still very very conservative because the high side moset is basically being turned on and off hundreds of thousands of times a second it doesn't stay on uh continuously so you can actually expect it to do quite a bit more than the 13 amps uh continuous rating even in this uh terribly cooled scenario that it's in um the high the low side fat is 23 amps uh continuous and that rating is actually realistically what it will actually be able to handle uh in this application because the uh lows side fat is turned on for most uh most of the time when in AVR M so that one spends a lot of its time turned on uh so you know we have 13 amps uh well not even 13 let's say you know 15 or 16 amps per per IC in each phase so that gives us about 30 amps for each given phase two phases total you have 60 amps uh you know if you don't go by the absolute worst case scenario and if you go by worst case possible scenario then it's 50 2 amps because that's the uh high side mosfet's continuous rating for no proper cooling scenarios um and this is again ridiculously Overkill the gddr5x um on a 1080 pulls around 30 Watts which with the voltage it runs at works out to around 22 amps so you know we have a we have a 52 amp memory vrm here so gigabyte went ridiculously over and I suspect it's again because there's no proper airf flow in this area due to the lack of the fan so yeah uh does mean that if you actually try to get some air flow into the shroud of the card this vrm is just going to be amaz like perform amazingly and in its stock configuration it's also perfectly good because gigabyte really did go insanely overkill on everything just to make sure that it can uh function in the less than optimal cooling environment that they've uh decided to go with on the water Force um whereas the gaming extreme the while know the extreme gaming so that's the air cooled version of this card that one would actually have a heat sink here with proper air flow over the entire vrm section so that one would actually arguably probably be a you know have better uh vrm capabilities not that it really matters CU this is a GTX 1080 and even in these less than sub you know in these complete suboptimal cooling scenarios the vrm setup that gigabyte has opted for is so ridiculously overkilled that it really doesn't matter they're like you're not going to see a GTX 1080 use anywhere near the full capacity of this vrm I'll be surpris like not even 50% of the capacity of this vrm will ever really be used so yeah very nice uh very nice PCD from gigabyte here and props to them for Designing such a ridic ridiculous monstrosity if you think about it um so that's that for the PCB breakdown uh like the video if you liked it subscribe to the channel if you haven't subscribed yet and do consider uh you know donating to uh Gamers Nexus on patreon so we can keep bringing you more content in the future thank you for watching and see you next time\n"