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XPS 9560 NVMe drive only running with two lanes of PCIe
I have a dell XPS 9560 which was purchased with maxed out on specs. Unfortunately it came with the lower performance 1Tb Toshiba drive. I decided to upgrade to the Samsung 970 Evo Plus, as I do a lot of work where IO speed is important.
I took the following steps to install the new drive1) Shut down the computer and physically replaced the drive.
2) Changed BIOS to use ACHI rather than RAID
3) Did a fresh install of Windows
4) Installed relivant chipset drivers from the dell web site
And.... I got the same bad bench mark results I had before... I looked into it a little further and according to CrystalDiskInfo and a couple of other utilities the current transfer mode is "PCIe 3.0 x2" where the supported mode is "PCIe 3 x4". This explains getting less then half the specified speed. Looking around I have seen perple getting numbers close to Samsung spec with the same computer configuration. Any help in getting my system to use the "supported" transfer mode with all 4 lanes/channels
Any help would be greatly appreciated!
P.S. This is a re-post as my original post disappeared.
jphughan
4 Operator
4 Operator
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14K Posts
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March 28th, 2019 13:00
I saw this reported once and the fix was to remove and reseat the SSD in the M.2 slot. The XPS 15 9560 definitely has a PCIe x4 interface and it runs in max performance mode, unlike the XPS 13 9350 and 9360, which have an x4 interface but run it in power saving mode instead, which gives essentially the same performance as an x2 interface.
thessm
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March 28th, 2019 15:00
Thank you for your response. I will try this right now and see if it helps. Your comment at least confirms that I should be getting a full 4 lane connection. I did recently get a motherboard replacement, which may have a barring on this, as I never checked the interface after the repair...
thessm
5 Posts
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March 28th, 2019 16:00
Thank you for the age old advice! When in doubt take it out and put it back in, but this worked like a charm. I now have all 4 channels, and benchmarks close to spec!