I bought a threadripper pro Thinkstation with a Threadripper PRO 3945WX. It’s got 128 pcie lanes but the power supply be default is proprietary and slots into the motherboard. It’s 1000W and has 2 8 pin pcie power cables coming out of the motherboard. I am wondering if anyone has ideas on how to have like 2 psus ATX or server and power a bunch of 3090s to have a good ML rig. something I’ve seen in the crypto mining world is this US Breakout Board Server Adapter PSU Power Supply 1200W HP GPU Mining W/ Cables | eBay
I think Lenovo locks the cpu to the motherboard so I don’t think I can just get a second motherboard and an adapter to use 2 24 pin psus.
Five 3090 needs about 2000W - 2500W PSU to properly saturate. Of course you can get away with lower if you undervolt.
Make sure your wall wiring support that kind of sustained load though!
There is a thing that I saw in someone’s YT video about mining cards or or a bunch of drives where they had a device that would into either motherboard header or existing PSU cable and detect if the PC is on and turn on a secondary PSU. I have no idea what it was called, but maybe you could look for something like that.
Based on past usage of ML, for medical EEG data the GPU isn’t going to ramp up that much if the OP is exclusively using Tensor cores. It’ll be closer to 1500W under real-usage conditions at best.
From my experience on the web development side, refitting Lenovo workstations/ThinkServe tower models required using an ATX plug mod to use either a 3rd party PSU or pairing PSUs. ThinkServe has more airflow than their desktops. There are adapters to run a 2nd PSU based on a shared header or pre-jumped PSU that stays on(a cheap PSU tester typically lets you keep a PSU running).
There are different versions of this Lenovo 14pin to standard 24 pin adapter:
https://www.newegg.com/p/284-005T-00002
The P620 is a nice machine, but you won’t be fitting more than one 3090 in it. It barely has enough space, power and airflow for 2 x RTX A6000 GPUs.
Unless you’re planning on running a couple of PCI extension cables out of the chassis, I’m not sure how you’re going to connect them.
As for ML, a single RTX A6000 Ampere in a P620 is a ton of compute for just one person. I have a few of these machines deployed in this configuration (CPU is 5975WX) and our ML Engineers love them.
Lenovo blows a “fuse” of sorts (known as PSB) only allowing the CPU to run on Lenovo motherboards, and yes, it sucks.
1 Like
yeah i was planning on doing a few risers but I don’t think it’s going to be able to work out with this setup.