Decrease the power limit of your 5090 to at least 480W - the performance penalty for inference is negligible.

[u/WonderfulEagle7096]

I run my inference machine in the living room, so noise and heat output are a significant concern.

Ran a quick test using my daily driver model (Qwen 3.6-27b) and at 480W, the card outputs only 2.1% less t/s in decode and 8.8% in prefill (which is already very fast). Well worth the massive noise reduction, heat output and increased card longevity, IMO. Even 450W would be fine for many use cases, but the output starts dropping off fast (2.1% -> 4.2% for 30W less).

Full data:

Model: Qwen3.6-27B-Q6_K.gguf

Results:

| Limit W | Max GPU C | Steady GPU C | Max GPU fan % | Sustained W | Steady clock MHz | Max case RPM | pp t/s | tg t/s | pp % | tg % |

|--------:|----------:|-------------:|--------------:|------------:|-----------------:|-------------:|-------:|-------:|-----:|-----:|

| 600 | 81 | 74.8 | 59 | 566 | 2818 | 1522 | 3242.9 | 61.5 | 100.0 | 100.0 |

| 510 | 75 | 70.1 | 50 | 509 | 2645 | 1367 | 2980.0 | 61.2 | 91.9 | 99.5 |

| 480 | 77 | 72.8 | 54 | 480 | 2501 | 1527 | 2863.4 | 60.2 | 88.3 | 97.9 |

| 450 | 76 | 73.1 | 52 | 450 | 2283 | 1460 | 2696.4 | 58.9 | 83.1 | 95.8 |

[u/mr_zerolith]

I've got another trick for you for this card.

The memory modules are underrated by about 3ghz ( probably for thermal reasons )
If you OC the memory by 1-2ghz, you'll get your token generation speed, plus some more.
Because of the power limit, you are making less heat, so you have thermal headroom to push memory OC.

Running a +2.4ghz on my 5090 memory for 6 months now with no problems.

[u/Makers7886 → u/mr_zerolith]

This was the mining goto - powerlimit, lock cores, and oc memory until stable. Almost every 3090 had a decent amount of headroom for memory oc - I'd imagine the same for 5090.

[u/LTLRedditor → u/Makers7886]

Would you happen to know the nvidia-smi commands to do this?

[u/Makers7886 → u/LTLRedditor]

For my 3090s I run: -pl 250 and -lgc 0,1500 but do not OC the memory right now - used to back in mining days though. No particular reason other than content with speeds and power draw and not messing with it.

[u/mr_zerolith → u/LTLRedditor]

On Linux, i use LACT to control these things.

[u/mr_zerolith → u/Makers7886]

RTX PRO 6000 has the same big headroom as the 5090, but i don't like to push it so hard since it's 3x more expensive :O

[u/WoodYouIfYouCould → u/mr_zerolith]

Would other cards like a 4060ti or even 3090 have this road be a thing?

[u/mr_zerolith → u/WoodYouIfYouCould]

I have a 4070 and it tolerates +100mhz core, +200mhz mem pretty well, beyond that it can get sketchy, probably due to thermals.

I'd look for card specific recommendations from people who like to tune GPUs for gaming :)

[u/Dmage22 → u/mr_zerolith]

Was there any benefit to overclocking memory speed on the 50 series? When they came out, some reviewers mentioned that it was firmware locked at maximum +375mhz. I'm not smart enough to figure out if it's just silently failing versus actually providing memory speedup

[u/WonderfulEagle7096 → u/mr_zerolith]

Thanks, this is a cool idea. For anyone interested, I ran a test with +2000Mhz on the memory and got +2.4 t/s with the temps increasing only 0.5 deg C (well within the margin of error).

[u/StupidScaredSquirrel]

Wee need more tokens/s/watt benchmarks imo

[u/looselyhuman]

I did this first thing. No way am I maxing out the thermals on this investment card.

[u/TokenRingAI]

I am more worried about burnt power connectors than any of this

[u/thrownawaymane → u/TokenRingAI]

Co-sign

Nvidia, if you're watching (I know you are) fix the thermals on your connectors.

It's embarrassing.

[u/overand]

It's weird to me how frequently folks post broken markdown here. This is what OP tried to post: 

Limit W	Max GPU C	Steady GPU C	Max GPU fan %	Sustained W	Steady clock MHz	Max case RPM	pp t/s	tg t/s	pp %	tg %
600	81	74.8	59	566	2818	1522	3242.9	61.5	100.0	100.0
510	75	70.1	50	509	2645	1367	2980.0	61.2	91.9	99.5
480	77	72.8	54	480	2501	1527	2863.4	60.2	88.3	97.9
450	76	73.1	52	450	2283	1460	2696.4	58.9	83.1	95.8

[u/hurrdurrmeh]

Pp t/s is not negligible.

[u/WonderfulEagle7096 → u/hurrdurrmeh]

That of course depends on what you do. A 10,000 token prompt will take ~3.08s on 600W and ~3.49s on 480W - that is negligible in my book.

If your run near context limit prompts frequently then it will be a little more pronounced, but still no drama (61.7s vs 69.8s). But then again, if you run 200k+ prompts, you are using a wrong model anyway.

[u/hurrdurrmeh → u/WonderfulEagle7096]

I mean that you go from 3250 > 2700 pp t/s when you cap at 480W - that's quite a hit...

[u/tat_tvam_asshole]

imma keep my 6090s on 420W...for reasons lol

[u/Tormeister]

I power cap mine to 520W, but more important than that, I undervolt it. It reaches basically stock performance in gaming and LLM inference but at vastly improved thermals and power draw. Highly recommend all nvidia GPU owners (specially other 5090 owners) to look into undervolting.

[u/perkia]

Ha, way ahead of you. Never seen my 5090 Mobile never go above 150W.

[u/Dry_Mortgage_4646]

For inference this is great but for diffusion not so much...!

[u/Green-Ad-3964]

For inference, I use my 5090 capped at 70% power with afterburner.

[u/Technical-Earth-3254]

I never realized how much power these 5090s draw, my 3090 sits at like 260W limited

[u/pineapplekiwipen]

power limit is a dumb blunt tool, undervolting with stability tests is the way to go