I'm aiming to build a super powerful desktop for CUDA calculations, specifically for MD simulations. I want to use a Ryzen 9590X, or an equivalent Intel processor like the Ultra 9 285K. My main requirement is to find a motherboard that can support 4 RTX 5090 GPUs at full or near full performance. It's worth noting that my focus is on CUDA performance rather than video output, so I'm uncertain about the importance of PCIe speeds. I'm not interested in server-grade options like Threadripper or Xeon—just a solid consumer desktop setup.
1 Answer
Unfortunately, you'll struggle to achieve full performance with 4 GPUs on a standard desktop motherboard. Both Intel and AMD desktop platforms offer a limited number of PCIe lanes—typically around 24. Each GPU usually requires 16 lanes. While some motherboards may allow you to slot in 4 GPUs, they won’t have enough lanes to support them fully, which could hinder performance for your CUDA calculations.
Gotcha. Do you know of any desktop motherboards that can still run 4 GPUs? Maybe a setup that provides decent performance, like 2 GPUs at x8 and 2 at x4?