I’m looking for a PSU for multiple GPUs build for local LLMs (probably 3-4 3090, maybe in the future 5090 instead) and I wonder what possible solutions do I have here? I live in Europe, so 230V installations here. I haven’t decided if it will be completely separate build in some kind of open mining rig or some server tower case (if you have any recommendations, they’re welcome) and serving as replacement of my current PC, so something that is quiet is welcome. I’ve noticed some people are using multiple PSUs, but I’ve heard it’s not recommended? So could you please provide your recommendations how to approach this problem? Is possible, I’d like to future proof my built from PSU and case perspective.
So I guess my questions consists of two parts - which PSU to get and is that possible to have reliable build having 3-4 GPUs in server tower case?
If you can put all GPUs into one case depends on your GPUs and the airflow they need. That then dictates what Mainboard you can use.
Regarding the PSU: I like Seasonic a lot, none ever broke for me, so that’s what I’ll keep buying. Select something with a high number in years of warranty from a brand name you trust. Living in 230V land myself I would choose a single PSU, 4 GPUs and 2 PSUs in one case will limit your selection of cases, but it’s possible. 4*600 W = 2400 W and the rest of your system would also like some power, so you are limited to small selection of the brand new 3000+ W PSUs that were just introduced at Computex.
I hope the wiring in your house can supply that much safely! That doesn’t change if you opt for multiple PSUs, I doubt you have multiple circuits where you want to plug in. When using multiple PSUs, also don’t cheap out on the power strip.
You don’t say where in the world you are and what your breakers can handle. Over 1500Watts you’re SOL in the west unless your house/office is wired for Nema6 and up.
I have been really impressed with the SilverStone zeus line, in particular the 1600R+ which can do 4x 300w gpus or 2x 600w gpus with a decent amount leftover for the rest of the system.
Beyond that you need 220 only PSU which they also have some 2-3kw psu as wlel.
If we’re talking about 3090s, why not power limit them? At 250~275W you get maximum efficiency, and 4x of those should require around 1000~1100W, so a 1.6~2kw PSU should handle it fine depending on the rest of your setup.
AFAIK you can’t go lower than 400W for those, so you’d be looking at 1600W+ alone for the GPUs.
If you choose that path, be aware that the boards are not all equal.
They are more or less tailored for the PSU power rating and size of the connector.
And you might need those PCIe extension cables, if your building in an open chassis.
It’s a funky solution that arises some controversy but it’s effective and “cheap”, when compared to the standard solutions.
