I think the point of negative returns for gaming is going above the RTX PRO 6000 Blackwell + AMD 9800X3D CPU + latency optimized RAM + any decent NVMe drive. Seems to net ~1.1x more performance than a normal 5090 in the same setup (and both can be overclocked about equally). Aside from what the GPU is optimized for, the CPU in these servers being ARM based ends up adding more overhead for games (and breaks DRM) which still assume x86 on Windows/Linux.