WDS256G1X0C - Poor seq. read performance

Hi everyone.

I have just bought a Lenovo Y520 notebook which has a WDS256G1X0C SSD drive in it.
All drivers are up to date everything works fine, but I get low speed values with this SSD.
Im using Intel RST driver. My OS is windows 10 and it was installed in UEFI mode on a GPT based partition on the SSD. My CPU is fast eough: CPU is i7-7700HQ, I have 16 GB DDR4 RAM, OS is a clean install (twice). The partition layout is 60+190GB, and I only have the OS so far, so lack of free space cant be the issue either. I run some diagnostics as well, and no errors were reported by any of those tools.

Sequential reed speed is just 1100-1200 MB/s while according to WD’s homepage it should be above 2000 MB/s.
SSD

The other values are more or less ok but the seq read speed is just way too low. I get similar results by using a different benchmark tool, like atto.

So…whats wrong with this SSD?