I attached mutiple PCIe card to AMD 64 bits Server which BAR size defines as 256GB. But linux can not allocate space for this pcie card. If there's no chance to uses PCIe BAR size over 256GB, could someone can tell me the max pcie BAR size. Thanks.
Try posting your question at AMD Forum Server Gurus which deals with everything to do with Server hardware and software: https://community.amd.com/t5/server-gurus/ct-p/amd-server-gurus
That is no one else answers your post here.
NOTE: What are the Make & Model of the GPU Cards your are using and amount of VRAM installed in each? Are they Professional AMD GPU Cards or Consumer GPU cards?