Powering a Rig with Mixed PSUs

Posted by d00m_sayer@reddit | LocalLLaMA | View on Reddit | 4 comments

I'm researching dual PSU setups for multi-GPU rigs and see a consistent warning: Never power a single GPU from two different PSUs (e.g., pcei slot power from PSU #1, 8-pin connectors from PSU #2). The reason given is that minor differences in the 12V rails can cause back-feeding, overheating, and fried components. For those of you with experience: Have you seen this happen? What were the consequences? What are the proven best practices for safely wiring a dual PSU system? do I need to use risers with pcei power isolators ? I've checked these and they have very limited length and are unfeasible for my rig.

4 Comments

[-]

JockY@reddit

If 240V is an option for you then the Flower Leadex 2800W PSU saves a lot of messing around. I run one off a re-purposed clothes dryer machine circuit (I’m in North America where 120V is standard).

BenniB99@reddit

I have used Add2PSU Adapters to integrate multiple PSU into a single rig, so far without any issues. You might want to check out SlimSAS cables and their corresponding host and device adapters. This will be much more flexible than risers and also much more stable (less pcie errors, better signal integrity). On the other side it might also get a bit more expensive, but it is worth it imo :)

No_Afternoon_4260@reddit

Yes, never had an issue. A atx psu for the system and a 12v server psu with a mining breakout board for the gpus

a_beautiful_rhind@reddit

The GPU power on my server is dead so I bought a breakout board for another server PSU. That's how I've been powering everything for more than a year. As long as you aren't buying crap PSU, it will probably be fine.

Reply to Post

4 Comments