Viewing a single comment thread. View all comments

rikonaka t1_j3jvvne wrote

Reply to comment by rikonaka in Building a 4x 3090 machine learning machine. Would love some feedback on my build. by soupstock123

I read your shopping list, there's has two problems, the motherboard and power supply, the power of one 3090 is 350 watts, and the power of four is 1400 watts, so your power supply should be at least 2000 watts (The specific calculation will be made after the CPU is determined), the problem with the motherboard is that the b650 does not support four 3090 video cards, and it only has two videos card slots.😉

1

soupstock123 OP t1_j3jx9ko wrote

Yeah, there's no way to add two PSUs on the pcparpicker, so that's mean to be 2 of the 1000W ones.

The b650 supports 4. It has enough ports. The blocking is not an issue because I'm going to be using GPU risers to fit the 4 GPUs.

To respond to your first comment, the thread ripper is also very expensive, and I'm waiting until Sept 2023 when threadripper 7 comes out and drops prices for thread rippers.

1

rikonaka t1_j3jyzos wrote

Well, I’m not sure how feasible the method of two power supplies for one host is😂, and it’s still a problem with the motherboard. I can’t comment on the stability of the method of connecting four 3090s using graphics card expansion (because I haven’t done so yet), I think you should carefully consider your plan, the cost of trial and error is not low.

1

qiltb t1_j3kjvki wrote

I actually works very well with ADD2PSU connector (used like 5 PSUs for one 14x3090 rig). He should actually think more of getting 1600W HIGH QUALITY PSU.

Corsair RM series IS NOT SUITABLE for workload you are looking for. Use preferrably AXi series or HXi if you really want to cheap out. We are talking about really abusing those PSUs. AX1600i is still unmatched for this usecase.

1

soupstock123 OP t1_j3l0lhk wrote

Thanks for the advice, can you elaborate more about how the Corsair RM series is not suitable for the workload? My rationale was that because it's an open air mining frame instead of a case, I wanted the RM series which supposedly is quieter?

1

qiltb t1_j3l9hll wrote

Under full load, AXi series is basically silent. But main reason is that PSU is not of high enough quality to actually sustain that load (even higher grade PSUs like EVGA P2 series has problems with infamous 3090 under DL task load) . Also take a look at my big comment on this reddit post.

1

soupstock123 OP t1_j3mteu8 wrote

Hmm, the Axi1600 might not be enough for me. This is my new build: https://ca.pcpartpicker.com/user/sixartsdragon/saved/DCh6Q7 and I'm looking at 1821W, so realistically I'm looking for a 2K PSU. I've chosen a Super Flower Leadex 2000 for now? What do you think?

1

qiltb t1_j3o7ull wrote

I actually assumed you will be having 2 PSUs. For least problems, buy 2xAX1600i, for cheaper option buy 2xAX1200i. One PSU is actually the worst case, but yeah you can try with a single SFL 2000.

1

soupstock123 OP t1_j3of5oq wrote

What do you mean least problems and why is one worst case?

1