How far down can you downvolt the rtx 4090?

[deama]

So I'd like to get the best GPU money can buy, but I hate how much power it uses, and out of principle, I would not like to use a GPU above 200W.

So I was wondering if you can just downvolt it to around 200W? Is it possible? I heard at some point it starts stuttering if you set it too low with the power limit option, and someone else said it has a limit of 300W with voltage curve.

Anyone tried going down that low without any weird issues etc...?

 

[deama]

Undervolting like overclocking suffers from diminishing returns, I suspect 200w is well below optimal. The video from tech yes is pretty good on this subject.

Yes I watched that one, but what I'm interested is whether the card can even go down to 200W without getting any weird stutter issues or whatnot.
I'm fine with lower performance, just don't want stuttering issues or weird stuff happening with the GPU.

 

[deama]

At 50% power limit the boost algorithm probably doesnt have enough room to manuver since the GPU will need a minimum voltage (probably 0.7V) to function correctly. Normally the boost algorithm can adjust the voltage and frequency to meet the power target, but since you would set the power target so much lower than is normally expected there is very little if any of the boost curve allocated to that performance region, hence the odd behaviour.

Probably the best bet to make this work is with a fixed clock, this is done by locking the voltage in the curve editor and then testing for the highest stable frequency at that voltage. With this method you dont actually set the power target.

I dont have a 4090 so cant give you an direct example, but this is roughly what you are proposing looks like on an Ampere 3090 .

Yeah that's what the guy on the video said and what I was thinking of doing. Problem is though I donno if I can go down that low, I heard you can't and it's capped in the BIOS of the GPU?

 

[deama]

What's the point? It's like saying I bought a Bugatti Chiron Super Sport 300+ but I don't like wasting petrol so I drive at 10 mph everywhere.

I just want the best performance I can get at 200W, so I thought buying the best card and just downvolting it would do the trick, because buying e.g. a 4080 and downvolting it to 200W would probably give worse performance than 4090 at 200W.

 

[deama]

You barely need to worry about such things. Most games go over 120fps at 4k. Set a frame cap limit in Nvidia control panel and you're 300w in most games. Then when you need extra power for the games where it can scale up.

Yes but that's at 300W, I need to go down another 100W.

 

[deama]

Hmm, ok I'll have to wait for the 4080 or maybe 4070 then.

Maybe I'll try AMD too, but not sure because I do machine learning on the side, so I'd need at least pytorch etc... to work with amd without too much of a performance loss (hopefully no quality loss).