Don't Undervolt the RTX 4090.

**GPU Undervolting on the RTX 4090: A Comprehensive Analysis**

---

### Introduction to GPU Undervolting

GPU undervolting is a technique where we reduce the operating voltage of a graphics card while maintaining the same clock speeds. This method has traditionally been a "cheat code" for enhancing GPU performance, allowing users to achieve lower temperatures, reduced power consumption, and quieter fan operations without sacrificing performance. For older generations like the RTX 3090 and RTX 2080 Ti, undervolting consistently delivered these benefits almost every time it was attempted.

---

### Differences with the RTX 4090

However, things take a different turn with the RTX 4090. When experimenting with clock speeds and voltage adjustments on this latest GPU, we observed unexpected behavior. Unlike previous generations, undervolting on the RTX 4090 results in a slight performance drop. This phenomenon was clearly demonstrated through testing: while the GPU clock remained consistent between the stock and undervolted settings, the effective performance metrics (measured in FPS) showed a noticeable reduction when undervolting was applied.

---

### Technical Analysis: Clock Speeds and Voltage Impact

To understand this anomaly, we examined the RTX 4090's clock speed behavior under undervolting. Typically, GPU discussions revolve around the GPU clock; however, there are two additional critical metrics to consider: the video clock and the effective clock.

- **Previous Generation Behavior (e.g., RTX 3090):** When undervolting was applied, these secondary clocks either remained stable or slightly increased alongside the primary GPU clock.

- **RTX 4090 Behavior:** In contrast, enabling an undervolt profile caused both the video and effective clocks to drop significantly. This suggests that these metrics are closely tied to the GPU's voltage level, possibly as a protective measure against unintended tuning.

This close coupling of secondary clocks with voltage levels introduces complexities not seen in previous generations. It raises questions about how NVIDIA handles power management and thermal regulation on the RTX 4090.

---

### Testing Results: Performance and Power Consumption

Our testing revealed that undervolting the RTX 4090 results in a modest performance hit, with only a few FPS lost. However, the benefits in terms of power consumption were substantial—reductions ranging from 70 to 80 watts were observed. These savings translate to lower thermal outputs and quieter operations, which are significant for systems prioritizing efficiency.

Despite these gains, we noticed inconsistencies. Attempts at more conservative undervolting (e.g., setting the GPU clock slightly higher while maintaining voltage) did not yield the expected performance improvements. In some cases, increasing the GPU clock resulted in a loss of a few FPS despite only modest power savings, making such adjustments less appealing.

---

### Limitations and Observations

One peculiar limitation encountered with the RTX 4090 is the inability to set voltages below 0.905V using tools like MSI Afterburner. This cap prevents users from achieving the extreme undervolt profiles seen in previous generations (e.g., 800mV on the RTX 3090). While this restriction might be a protective feature, it limits the potential benefits of aggressive undervolting and essentially nerfs the card's performance.

---

### Conclusion: Undervolting on the RTX 4090

In summary, undervolting remains possible on the RTX 4090 but with caveats. While power consumption and thermal outputs can be significantly reduced, there is a noticeable (albeit small) drop in performance. This behavior, coupled with voltage restrictions, makes undervolting less appealing compared to previous generations.

Interestingly, the RTX 4090 already exhibits impressive thermal and noise characteristics out of the box, rendering undervolting somewhat redundant for many users. In typical gaming scenarios, the GPU consumes between 370-390 watts, which is already a reduction from expectations of up to 450 watts.

For those eager to maximize efficiency gains, undervolting can still be considered but with tempered expectations. The RTX 4090's performance under undervolt conditions is not as optimal as its predecessors, and users must weigh the benefits against potential drawbacks.

In conclusion, while undervolting on the RTX 4090 is feasible, it's less impactful than in previous generations, and users should approach this technique with a clear understanding of its limitations.

"WEBVTTKind: captionsLanguage: enso we've seen some massive results from GPU undervolting in the past gpus like the 3090 the 2080 TI undervolting has always been really worthwhile almost all of the time you can get lower temperatures lower power consumption and fan speeds all while at the same performance it's almost like a cheat code for making your GPU just run better but things are very different here with the RTX 40 series at least the 4090 that I've tested here once you start fiddling around with the clock speeds and the voltage it behaves very differently and starts doing some really weird things now for those who don't know what GPU undervolting is essentially what we're doing is just reducing the operating voltage of the GPU so if it normally runs at 1900 megahertz one volt we're just going to run it now at say 0.9 volts still at the same clock speeds though so that we get the same performance but since it's now at a lower voltage that means that we get lower power draw and lower thermals as well except if you do exactly that on the RTX 4090 you do actually get a decrease in performance this comparison shows pretty well in a nutshell of what is happening left is completely stock and over on the right is undervolted but matching the same clock speed just like our usual method and we usually don't see a performance drop but here we do it's not a huge decrease and yeah we do get some really nice power reductions here as well but this just shouldn't be happening like it's just not the expected Behavior after all the clock speeds are identical in both comparisons at least close enough so there really shouldn't be any performance difference so let's take a closer look at what's Happening Here booting up Hardware info with furmark in the background we can see that there are actually three clock speed values there's the GPU clock which is what we're typically referring to when we talk about clock speeds then there's also the video clock and the effective clock here we're looking at the previous gen 3090 and notice that when I enable a GPU undervault the video clock and the effective clock don't do much in fact they actually go up a little bit because I've also increased the regular GPU clock a little bit but then take a look at what happens when we do the exact same thing for the new RTX 4090 when the undervolt profile is enabled both the video clock and the effective clock drop by a fair chunk so despite our GPU clock appearing to be the same as what we'd get out of the box we actually get lower performance because these other clock speeds are lowered in the background it seems that both of these values are a lot more closely tied to the actual voltage that the GPU is running at for this generation probably acting as a safeguard of some sort if I had to guess so yeah it's the usual undervolts method but a very different result it's doing some weird quirky stuff in the background for this generation which makes me a little bit uncomfortable your GPU clock appears the same again but in reality your gaming performance will be slightly lower in this comparison for example our GPU clock is actually slightly higher than stock but there's a few FPS reduction now of course the obvious perspective of this is damn you get a pretty massive 70 to 80 watt decrease for pretty much the same performance that seems like a pretty trade it off and yeah I can totally see that you're not really going to notice that few FPS difference but the power and temperature reduction on the other hand will be a lot more noticeable but I just don't really feel that comfortable honestly recommending it when it looks like the GPU is trying to regulate and protect itself from the tuning that we might be doing I did also try more conservative undervolting around 2 800 megahertz at one volt flat which would actually represent an overclock but even then we're not able to get the full stock performance of the 4090 which I just found super weird in this comparison for example our less conservative undervolt has the GPU clock 70 megahertz higher but it's oddly a couple of FPS behind and at that point we're only saving about 30 watts of power and it's not really worth enabling also something really weird when it comes to undervolting on the 4090 you can't set any voltages below 0.905 volts so 0.9 volts you actually can't go below that so if you set an MSI afterburn example 850 millivolts it will just kind of cap you at 905 millivolts instead which is really weird I've never seen that you know previously on the 3090 you could go as low as 800 millivolts for example and get like some crazy efficient undervolt profile but here that is just not doable anymore which I don't really recommend going to those super low voltages anywhere you're kind of just nerfing and underclocking the card which you know for a flagship not really worth doing but still kind of an interesting point to note so look if you're absolutely desperate to reduce the power and thermals on this thing it is possible you can do it it seems safe enough from the testing that I've done here's an overall snapshot of what you can expect just keep in mind that there will be a slight performance drop this time around and that there seems to be some weird stuff happening in the background that to be honest I just don't really understand most notably the effective clock and the video clock which seem to be directly tied to the voltage of the card for this generation I also feel that this time around you really don't need to be undervolting the 4090 like yeah it runs at quite high power but the thermal and noise performance out of the boxes actually pretty impressive you can reduce those factors even further with undervolting but definitely knowing you're as drastic as what we saw with the 30 series but on the bright side typical gaming scenarios will usually have the 4090 sitting around the 370 to 390 watt Mark which already kind of feels like a power reduction compared to the 450 Watts that a lot of people were expecting so hopefully you found this interesting or at least helpful if you are planning on buying a 40 series GPU as always a huge thanks for watching and I'll see you all in the next oneso we've seen some massive results from GPU undervolting in the past gpus like the 3090 the 2080 TI undervolting has always been really worthwhile almost all of the time you can get lower temperatures lower power consumption and fan speeds all while at the same performance it's almost like a cheat code for making your GPU just run better but things are very different here with the RTX 40 series at least the 4090 that I've tested here once you start fiddling around with the clock speeds and the voltage it behaves very differently and starts doing some really weird things now for those who don't know what GPU undervolting is essentially what we're doing is just reducing the operating voltage of the GPU so if it normally runs at 1900 megahertz one volt we're just going to run it now at say 0.9 volts still at the same clock speeds though so that we get the same performance but since it's now at a lower voltage that means that we get lower power draw and lower thermals as well except if you do exactly that on the RTX 4090 you do actually get a decrease in performance this comparison shows pretty well in a nutshell of what is happening left is completely stock and over on the right is undervolted but matching the same clock speed just like our usual method and we usually don't see a performance drop but here we do it's not a huge decrease and yeah we do get some really nice power reductions here as well but this just shouldn't be happening like it's just not the expected Behavior after all the clock speeds are identical in both comparisons at least close enough so there really shouldn't be any performance difference so let's take a closer look at what's Happening Here booting up Hardware info with furmark in the background we can see that there are actually three clock speed values there's the GPU clock which is what we're typically referring to when we talk about clock speeds then there's also the video clock and the effective clock here we're looking at the previous gen 3090 and notice that when I enable a GPU undervault the video clock and the effective clock don't do much in fact they actually go up a little bit because I've also increased the regular GPU clock a little bit but then take a look at what happens when we do the exact same thing for the new RTX 4090 when the undervolt profile is enabled both the video clock and the effective clock drop by a fair chunk so despite our GPU clock appearing to be the same as what we'd get out of the box we actually get lower performance because these other clock speeds are lowered in the background it seems that both of these values are a lot more closely tied to the actual voltage that the GPU is running at for this generation probably acting as a safeguard of some sort if I had to guess so yeah it's the usual undervolts method but a very different result it's doing some weird quirky stuff in the background for this generation which makes me a little bit uncomfortable your GPU clock appears the same again but in reality your gaming performance will be slightly lower in this comparison for example our GPU clock is actually slightly higher than stock but there's a few FPS reduction now of course the obvious perspective of this is damn you get a pretty massive 70 to 80 watt decrease for pretty much the same performance that seems like a pretty trade it off and yeah I can totally see that you're not really going to notice that few FPS difference but the power and temperature reduction on the other hand will be a lot more noticeable but I just don't really feel that comfortable honestly recommending it when it looks like the GPU is trying to regulate and protect itself from the tuning that we might be doing I did also try more conservative undervolting around 2 800 megahertz at one volt flat which would actually represent an overclock but even then we're not able to get the full stock performance of the 4090 which I just found super weird in this comparison for example our less conservative undervolt has the GPU clock 70 megahertz higher but it's oddly a couple of FPS behind and at that point we're only saving about 30 watts of power and it's not really worth enabling also something really weird when it comes to undervolting on the 4090 you can't set any voltages below 0.905 volts so 0.9 volts you actually can't go below that so if you set an MSI afterburn example 850 millivolts it will just kind of cap you at 905 millivolts instead which is really weird I've never seen that you know previously on the 3090 you could go as low as 800 millivolts for example and get like some crazy efficient undervolt profile but here that is just not doable anymore which I don't really recommend going to those super low voltages anywhere you're kind of just nerfing and underclocking the card which you know for a flagship not really worth doing but still kind of an interesting point to note so look if you're absolutely desperate to reduce the power and thermals on this thing it is possible you can do it it seems safe enough from the testing that I've done here's an overall snapshot of what you can expect just keep in mind that there will be a slight performance drop this time around and that there seems to be some weird stuff happening in the background that to be honest I just don't really understand most notably the effective clock and the video clock which seem to be directly tied to the voltage of the card for this generation I also feel that this time around you really don't need to be undervolting the 4090 like yeah it runs at quite high power but the thermal and noise performance out of the boxes actually pretty impressive you can reduce those factors even further with undervolting but definitely knowing you're as drastic as what we saw with the 30 series but on the bright side typical gaming scenarios will usually have the 4090 sitting around the 370 to 390 watt Mark which already kind of feels like a power reduction compared to the 450 Watts that a lot of people were expecting so hopefully you found this interesting or at least helpful if you are planning on buying a 40 series GPU as always a huge thanks for watching and I'll see you all in the next one\n"