Showing results for 
Search instead for 
Did you mean: 

Z170-A plus Samsung SSD speed problem

Level 7
Hello! I hope I can find the solution of my problem here.

I have a motherboard Asus Z170-A (BIOS version is 3802) and have connected Samsung 970 EVO Plus 2TB SSD to M.2 port (the drivers are installed).
In the BIOS section Onboard Devices Configuration tab, the SATA Mode Configuration option is set to SATA Express.
The PCI-EX16_3 Bandwidth option switched from Auto mode to X4.

As a result of tests, the disk read speed is 890MB/s, the write speed is 878MB/s.
The drive runs on a PCIe Gen.3 x1 interface (although in theory it should work on x4).

Connected devices:
AMD Radeon R9 200 Series video adapter to PCIEX16_1 port.
Corsair Force LS SSD (SATA-III) to SATA6G_3 port
Disk drive ST4000NM0033-9ZM170 (4 TB, 7200 RPM, SATA-III) to SATA6G_4 port

CPU type QuadCore Intel Core i7-6700K, 4200 MHz (42 x 100)
Memory module: Corsair Vengeance LPX 8 GB DDR4-2400 DDR4 SDRAM - 4 pcs (Total 32GB).
Windows 10

Can somebody help me to get a full speed and run SSD with PCIe 3.0 x4 transfer mode?