undefined

points

[-]

It's quite nuanced. In a nutshell the unlock just flips the 2 bits that halves how often the core can issue the specific instructions Nvidia locks to full rate on the professional and datacenter cards.

Obviously doing more compute requires more power but what it does is shift the card down on the frequency curve to keep the wattage in check. So you're right that at stock power limits it hits a cap where the full issuing rate isn't reached but it depends heavily on the exact workload how much juice is left.

The frequency curve also takes heat into account so in general you end up with a nice perf boost for a slightly hotter card.

I've been running this on my 2 3090s for a month now with no issues but they are also water cooled :-)

by jacquesm19 hours ago|

parent|

[-]

Ah, that's a twist I didn't see coming, all my GPUs are aircooled. I can see how with watercooling you'd be able to get more performance out of the GPU before hitting the limits.

by BoorishBears18 hours ago|

parent|

prev|

[-]

There 3090 is from the era of overclocking, anything but the reference design should be fine even on air cooling (especially if you have a 3 connector model)

My EVGA came with stock firmware that started at a 420W and allowed up 500W, of course 500W did nothing for gaming

by Tiberium20 hours ago|

prev|

[-]

> - you will need to run your card hotter than you might be comfortable with

Can you explain this one? On my GPU I didn't have to change the power limit. Obviously the card might spend more time at max power usage, but it's still within the limit.

by jacquesm20 hours ago|

parent|

[-]

If you increase the power limit on the card you will be able to get much more mileage out of this modification. At 450W the difference is much, much larger but that is not something I'm comfortable with doing for longer runs. Note that the stock settings are already pretty extreme for that cooler, and that ambient temp and free airflow are going to be impacting the resulting GPU temp in a very direct way. I have my 3090's in an external box (with its own separate PCIe backplane) so they can talk p2p and have 'fresh air' rather than in the enclosure.

by Tiberium20 hours ago|

parent|

[-]

Yes, but you can get up to a 40-50% increase in some workloads even with the same power limit, and some cards have it locked anyway. I just felt like it was a litle misleading for you to mention the power in your original post, since the unlock works regardless of that.

by jacquesm20 hours ago|

parent|

[-]

Interesting, I have 7 3090's here of different plumage and they all require a power increase to get > 25% gain with this modification, would you mind sharing the type of card you have and how it is cooled?

Obviously, if there are 3090's out there that respond differently then I will be happy to retract that.

by unsnap_biceps19 hours ago|

parent|

prev|

[-]

Is your external box something you put together or is it a product you purchased?

by jacquesm19 hours ago|

parent|

[-]

I put it together myself. It was a lot of work and I learned a lot of nasty lessons along the way. The short version of the recipe:

- get the largest PSU you can find (1500W at a minimum, more is better)

- get the ADT PLX Quad PCIe backplane. Run 4 thin (single slot) GPUs inside your main enclosure, stick the ADT interface board in between two of the thin boards (don't stack them close to each other or they won't be able to breathe).

- ensure you have as much or more RAM as you do VRAM

- Ensure your CPU has enough PCIe lanes to run at least five boards in x16 (four for the GPUs in the main enclosure, another for the PLX PCIe switch)

- In the BIOS set BAR1 to 'resizable' and > 4G decoding should be enabled.

- ditch the cables that come with the ADT board, they may work but there are much better ones out there and they're not expensive, this will save you days of troubleshooting

- Build your own enclosure rather than trying to adapt a standard one, it won't work anyway (the board pitch is wrong, as is the placement of the mounting holes).

- Put another four double or triple boards on the backplane.

- Add another 3x 140 mm fan to the front of the case so you get good airflow without the feeling of being next to a Harrier at take-off

- I used 3D printed parts to mount the PSU and the board as well as the fans (see below).

- Make sure the board is properly grounded to the enclosure

- If you're running 3090's or other cards that are P2P capable that were hobbled by NV then look at this https://github.com/aikitoria/open-gpu-kernel-modules driver module.

- Power on the ADT board, wait three seconds then power on the main machine. Enjoy your VRAM :)

If you have more questions please email me and I'll be happy to help out.

by augment_me20 hours ago|

prev|

[-]

These number claim 240W locked power draw on 4070:

https://github.com/JustAResearcher/gpu-unlock-ada/releases/t...

by jacquesm20 hours ago|

parent|

[-]

This is about the 30' series in principle, I don't have a 4070 here to test with (I do have a couple of modded 4090's) but I suspect that at 240W you are not getting the maximum out of that card. At the same time: that is probably pretty close to optimal in terms of tokens/W.