NVMe SSD PCIe 3.0 x4 capable running at PCIe 3.0 x1 speeds


New Member

Grateful for the wonderful hwinfo tool.

I have an Acer Aspire
R5-571TG-78G8 laptop.

I installed a Samsung PM951
MZVLV256HCHP 256GB NVMe SSD. Here are the specs of the SSD.

The SSD is running at PCIe 3.0 x1 speeds while it is capable of PCIe 3.0 x4 width, resulting in slower read/write speeds. Attached herewith are hwinfo and crystaldisk ssd test screenshots.


1. can someone explain why the PCIe bus x 2 is having maximum link width of 3.0 x4 but is running at 3.0 x1?

Thanks in anticipation


From what I found out on my Mother Board is 1 of 2 things going on here. 1. The BIOS is set to x1 for that slot even though it's an x4. 2. That slot is sharing another slot and maybe slowing both slots down.

Note: I can slow my x16 to x1, x2, x4, and x8. Plus, I can also change the PCIe 3.0 to 2.0 or 1.0.