The motherboard I’m using is Supermicro’s M12SWA-TF, I’m sure the BIOS has been updated to the latest from the official website, and the ASC has been turned off. But my situation is still the same, and I am not sure whether the 4090 supports P2P, because I see that the link you shared is running simpleP2P, and I have run simpleP2P
deviceQuery
p2pBandwidthLatencyTest. The result is in the attachment
IOMMU_enable_ACS_disable.txt (16.0 KB)
IOMMU_disable_ACS_enable.txt (16.1 KB)
IOMMU_disable_ACS_disable.txt (16.1 KB)