In fact, based on Intel chipset specification, when you install FSB800 CPU and two DDR 400 memory modules (to enable Dual Channel DDR feature) on this MB, PAT will be enabled automatically. But, as you saw the memory performance status of CPU-Z does not detect PAT mode but fast chip select mode. Thus, if you want to make the memory performance status of CPU-Z is enabled, please try to enable the "Fast Chip Select" option manually via BIOS setting later.