Power management of 7900XTX, to lower the power beyond 10%

[masterdeejay]

I bought one of these behemoths several days ago, specifically the even more ridiculous Sapphire Nitro+, and the power consumption is simply horrific. The OC BIOS that made the card eat 400W certainly didn't help either, lol. Even with the regular one it was a miniature oven installed inside the case, so I experimented for a while and realized the boost clocks were complete nonsense and had very little to none at all effect on frame rates. I limited the max frequency to 2300MHz while lowering the power limit to the max. allowable -10%, along with undervolting the card to 1080mV (from stock 1150 - is that the same on all cards?), and now the damn remains pretty tamed at 300W. And I still have 165fps most of the time in Delta Force on ultra details.

undervolt on these cards not lower the power usage, it just make the card to boost higher.
I have a 7900XT Nitro+ (not the XTX). Voltage is 1100mv default. Undervolted to 1050mv, it boost to 2900-3000mhz in games. (driver mhz sliders at default 2600mhz, that does nothing)
I only play at 60hz so most of the time the card is on 100-150w power.
So i think the fps limit is the only way to reduce power. (if possible)
Or maybe a silent bios.

 

[Macro Device]

That's all you need. 2150 is an arguable number, your sweet spot might be in a different place, RDNA2 (my GPU) is not RDNA3 (your GPU).

 

[Octopuss]

Yep, the frequency limit makes a lot of difference.

 

[kapone32]

Yep, the frequency limit makes a lot of difference.

I have my 7900XT in water and after undervolting my boost clock is 3100 mhz. The GPU does not go past 50 C on the core and as a result the card has no problem pushing myK 144hz monitor to the limit and beyond. The temps being so low does have the GPU drawing more power than not under water though. Just like in a car the heat goes through the rad but in the summer inside the case is about 6 degrees cooler than ambient. I am strongly considering getting the new C1 CPU block from Alphacool. I love their products.

 

[Octopuss]

Those blocks are very expensive though, are only compatible with exactly one card, and you need the actual (even more expensive) cooler on top of that, and I'm not even sure you can buy any AIO and connect it to the block, or you need something special. It would certainly be nice though, and I could fit the radiator at the top of the case where I have plenty of room.

On the other hand, the card never boosts above 2600MHz from what I could see (even undervolted), and capping it at 2300MHz made zero fps difference.

 

[kapone32]

Those blocks are very expensive though, are only compatible with exactly one card, and you need the actual (even more expensive) cooler on top of that, and I'm not even sure you can buy any AIO and connect it to the block, or you need something special. It would certainly be nice though, and I could fit the radiator at the top of the case where I have plenty of room.

On the other hand, the card never boosts above 2600MHz from what I could see (even undervolted), and capping it at 2300MHz made zero fps difference.

Alphacool can sell you every part of it. They even have GPU AIOs. The truth is that these cards are considered high end so blocks are usually available but Byiski makes blocks for just about every card out there and are not too expensive. Getting back to Alphacool, my block was for the 7900XTX Nitro. It fits perfectly with my 7900XT pulse. The pump res can be expensive but Corsair regularly sells their unit for $99. I also use Alphacool quick connect that is a combination of fittings, tubes and orings. They connect in such a way that I just unscrew 2 ports to remove my GPU. All told you would spend about $300 for a pump/res based system or about $180 for the AIO from Alphacool.

Newer Games will push these cards as far as they will go. Games like Space marine 2 love high performance machines.

It also depends on your CPU. From what I have seen my current CPU pushes 3-5 more GB/s to VRAM in Games.

 

[Octopuss]

What about the coolers though? I think I read all these AIOs will basically die within just a few years due to reaction between metals inside, more or less dissolving the insides into a mess that's no longer working even half properly. I used to have some notes made somewhere but lost them, and then I ditched the idea of a CPU cooler alltogether. A GPU though, especially one like this... that's another story!

 

[kapone32]

What about the coolers though? I think I read all these AIOs will basically die within just a few years due to reaction between metals inside, more or less dissolving the insides into a mess that's no longer working even half properly. I used to have some notes made somewhere but lost them, and then I ditched the idea of a CPU cooler alltogether. A GPU though, especially one like this... that's another story!

That is EK not Alphacool. All of their products are Copper plated. I have never had an AIO die on me. Even my Cooler Master Nepton 280 is still cooling a PC at my Sister. I even have one of those for a Vega 64 and the pump still works just fine.

https://shop.alphacool.com/en/shop/cpu-gpu-aios/gpu-aio/koi-alphacool-eiswolf-2-aio-360mm-rx-7900xtx/xt-nitro-with-backplate?currency=3

 

[redeye]

I bought one of these behemoths several days ago, specifically the even more ridiculous Sapphire Nitro+, and the power consumption is simply horrific. The OC BIOS that made the card eat 400W certainly didn't help either, lol. Even with the regular one it was a miniature oven installed inside the case, so I experimented for a while and realized the boost clocks were complete nonsense and had very little to none at all effect on frame rates. I limited the max frequency to 2300MHz while lowering the power limit to the max. allowable -10%, along with undervolting the card to 1080mV (from stock 1150 - is that the same on all cards?), and now the damn remains pretty tamed at 300W. And I still have 165fps most of the time in Delta Force on ultra details.

or set the max frequency to 2117, run everything at stock, (1150 mV). and it takes 300w on 3dmark speedway.

 

[QuietBob]

Setting the min/max GPU frequency and voltage sliders to their lowest values effectively locks the 7900xtx to 145 W TBP. I don't think it's possible to lower the power target even more, as you can't bring the memory frequency down from the default.

Of course the minimum voltage won't be stable in more demanding games, and the hit to performance with minimum GPU clock may also be too much. As has been said, we can experiment with different clock/voltage combinations to reach our desired TBP. Another way is to create game specific profiles and test for the lowest stable settings.