Terrible write speed, blazing read speed on RAID1 SSD RST

[steam2]

I have an i7-4770K with 32GB RAM on Gigabyte GA-Z87X-UD5H motherboard.

The OS is Windows Server 2016 running RST 15.8.1.1007. I have two Samsung 850 Pro SSDs in RAID1 setup and initialized.

It is very slow to boot and copy files.

Settings in RST:

Write-cache buffer flushing: Enabled

Cache mode: Off

Link Power Management: Disabled

Running MTI's Read-Write test benchmark, I get an anemic 25MB/s writes, but 900MB/s reads.

What can I do and/or check?.

[steam2 · Accepted solution]

Doh! I didn't install the chipset drivers it seems. After installing them (after installing all other system drivers), now it's getting respectable numbers:

429MB/s avg write

1057MB/s avg read

Hopefully this will help someone else.