Slow speeds on M.2 NVME SSD (Laptop)

[GouthamJalli]

So I've purchased and installed M.2 NVME SSD from Kingston 500GB. I already have a 250GB Samsung SSD as my primary on which my Windows was installed. So I ran the crystal disk mark test and got this weird result. Can someone say why my speeds are low? Please help.
Proof: https://ibb.co/YbfjzJt
By the way, I've changed my SATA mode from RST premium with optane to AHCI and ran the tests again, but still reading speeds are around 1200 mb/s. So below are my PCIe hardware details...Everything's fine, right?
Img: https://ibb.co/Hp402Jr

 

[vishalrao]

Can you look at the drives section for details? Perhaps your second slot is only running at pcie 3.0 x2 and not x4

 

[vivek.krishnan]

Could you also check and see what are the review speeds for your SSD?

 

[Rakesh_kumar]

Can you look at the drives section for details? Perhaps your second slot is only running at pcie 3.0 x2 and not x4

The same happened to me, I have Samsung 970 Pro and while I am using that on my laptop I am getting 50% of its original speed. Then I found out about bus lanes. My laptop has 2x lanes so the NVME speed reduced by half. Then after that, I have installed it on my computer, Boom, 100% speed as mentioned in specs. This might be the same issue.