PSU Sizing for Multi-GPU AI & Render Workstations

A single high-end GPU already pulls 300–450W under load. Put two or three of them in one chassis for AI training or render farming, and the power supply stops being an afterthought — it becomes the component most likely to bottleneck or crash the whole build if it's undersized.

Add up real draw, not marketing numbers

GPU-maker "recommended PSU" figures assume a single card and a modest rest-of-system. They don't scale linearly once you add a second or third GPU, because the CPU, storage array, and fans are drawing their own separate load on top. The right way to size a PSU is to add up every component's actual rated draw, not the smallest GPU-vendor number times the GPU count.

Component	Typical draw (multi-GPU build)
2–3× high-end GPU	600–1,350W combined
High-core-count CPU	150–280W
NVMe/SSD array + fans/pump	40–80W
Motherboard + RAM	60–100W

Then leave real headroom

Don't run near the rated max continuously — PSUs are least efficient and generate the most heat right at their ceiling; a sustained AI training run or overnight render is exactly the continuous-load scenario where this matters most.
Transient power spikes are real — GPUs under load draw brief spikes well above their steady-state number; a PSU sized to the exact steady-state total can still trip on a spike it never "should" have hit on paper.
Multi-GPU needs the right connectors, not just the right wattage — enough independent PCIe power cables/rails to feed every card without daisy-chaining connectors meant for one GPU across two.

Platinum/Titanium efficiency pays for itself here

A workstation that runs multi-hour training jobs or render queues draws near-peak power for long stretches, not in short bursts like a typical desktop. A few points of PSU efficiency compounds into a real difference in heat output and electricity cost over months of near-continuous use — worth the premium on a build that's actually going to run like this.

Every ProStation AI/ML workstation and render build is PSU-sized against the real component list, not a rounded-up guess — including connector count and continuous-load headroom. Configure your build or talk to us via a free consulting call if you're planning a multi-GPU rig.