Just ran disk mark against my two drives. Both are hitting their rated speeds at PCIe 3.0 x4. 1TB Samsung PM9A1 (stock main) and 2TB Pioneer APS-SE20Q-2T (added secondary). So it doesn't
Samsung Pm9a1 Ssd M.2 Ssd 256gb 512gb 1tb Nvme Pcie Internal Solid State Disk Hdd Hard Drive Inch Laptop Desktop Tlc Pc Disk - Solid State Drives - AliExpress