2x+ 4090s Single Machine

[FoldingAddict]

I'm not sure who has done this if anyone...but I'm curious before I go that route if anyone has run multiple (2 or more) RTX 4090s in a single box for the purposes of folding. GPU-Z reports my 4090 is most of the time pulling about 250-300 watts, that's on a +0 mem, +220 core, 106 power limit. If I were to back all that off and undervolt, I'm sure I could get the power draw down some without much impact to performance. The major question is transient spikes. Are transient spikes even common in folding or is the workload so balanced that they don't really happen? My main rig is running an EVGA 1000 watt PSU, 10850k stock, custom GPU/CPU loop with a 4090 Gaming X Trio and I'm really curious on educated guesses on if I can run two 4090s without a PSU upgrade on top. Thoughts? For info, this is project 18213 in GPU-Z, 100ms polling rate 302 watt max draw after 30 minutes.

 

[EarthDog]

There are transient responses to any change in load... for example, when you complete a WU and fetch/start another there would be some...

Me.........I'd try running F@H on 1KW PSU and two 4090s............. but, some people's paranoia about running things towards the end of their rating is higher than mine.

 

[FoldingAddict]

Basically I'm just asking somebody to tell me to pull the trigger so I can self-justify that it's for science.

 

[Holdolin]

I've done it. I have an older server board that used to have 4x Radeon VII Pro's in it for Milkeyway@home. I plopped my first to 4090s in there when I got them. Numbers were a bit off as compared to my current builds, but there are several differences between that setup and the setups I have for them now.

 

[FoldingAddict]

I've done it. I have an older server board that used to have 4x Radeon VII Pro's in it for Milkeyway@home. I plopped my first to 4090s in there when I got them. Numbers were a bit off as compared to my current builds, but there are several differences between that setup and the setups I have for them now.

Just curious what the rating was of the PSU in that machine?

 

[Holdolin]

I just left the 1600 watter that was already in the chassis. If/when I verify it was either the PICe v3 or something else that was causing the slowdown I'd consider going back to 2 GPUs per chassis, prolly using a 1000 watt PSU for them.

 

[EarthDog]

Just curious what the rating was of the PSU in that machine?

Just jumping in here, but efficiency doesn't take away from the output... it means it takes more from the wall.

 

[FoldingAddict]

I guess worst case scenario if I run into any issues I can throw it into one of two other servers, I just didn't want to because those mfers get hot already.

 

[Holdolin]

Just jumping in here, but efficiency doesn't take away from the output... it means it takes more from the wall.

Right on. Is why all my builds now use platinum PSUs. I've done the comparisons and was quite enlightened. Not that I ever doubted it, but just great to see theory turned real

 

[FoldingAddict]

Isn't the difference between gold and platinum at >50% only 2% efficiency?

 

[EarthDog]

Right on. Is why all my builds now use platinum PSUs. I've done the comparisons and was quite enlightened. Not that I ever doubted it, but just great to see theory turned real

2% difference does add up for folders/those who run load 24/7, but for regular users, you'll never make up the price difference between that and gold for the same wattage unit.

Isn't the difference between gold and platinum at >50% only 2% efficiency?

Yep.

 

[FoldingAddict]

Seems legit. I always target 80+ gold units although I was considering grabbing a new Seasonic 80+ platinum that has the native 12vhpwr cables.

 

[Holdolin]

Yes, it adds up quickly, and as EarthDog pointed out, running high loads 24/7 it's a game changer IMO. Even if I don't make up the price difference in power savings I'm more concerned with the ongoing operational (electric) costs than the build cost.

Post magically merged: Mar 16, 2023

Going purely from my just woke up memory, gold PSUs are what, 80%? The platinums are 90% as I remember. To put it in real world numbers, according to the watt meter on my UPS, the Prometheus with the old gold PSU she was drawing 480-500 watts. after changing only the PSE she now draws 400-410 watts.

 

[EarthDog]

Going purely from my just woke up memory, gold PSUs are what, 80%? The platinums are 90% as I remember.

Naa, the difference is ~2%...10% is 80 Plus to Platinum.

Edit: 4%

 

[FoldingAddict]

This is what I've always gone by:


I assume there would be differences +/- by some degree between manufacturers and individual units.

 

[Holdolin]

See, my memory confused the bronze with the gold. thanks for setting me straight guys

 

[EarthDog]

See, my memory confused the bronze with the gold.

...80 Plus with Platinum was 10/12%...Bronze to Gold is 7/8%.

I know, I know, I split that hair right down the middle... a stickler for facts...

 

[FoldingAddict]

Just bought 2 Looks like a server is getting one anyway.

Think I'll have to cut a hole out of the side and load up some Noctua 120s I have laying around lmao

 

[Farwalker2u]

This image shows my MSI Gaming Trio 4090 power draw. This has been running for a few days and the top wattage is 306.1. It is OC'd a bit.

I have a second 4090 folding as well. It is a MSI Gaming X Trio which seems to have had a max wattage pull of 271.9W (recent upgrade, which has only been running on this run for about 30 minutes).

If you are going to run two that would be 612 watts (I would add a safety margin of 10 - 20%), plus you need power for fans, CPU, RAM . . . . .

 

[FoldingAddict]

Yeah I picked up 2 more Gaming X Trios, same as my current one I just won’t be buying water blocks for them. Should be fine on power draw I think as long as I don’t try to game Main GPU while folding on the second GPU, that would surely cause a shutdown.