How to make NVMe SSD run at PCIe x4??

[TC326]

So I purchased a Samsung EVO 970 NVMe PCIe 3.0 x4 SSD to use in this laptop that I got super-cheap during a summer sale. Unfortunately, the SSD isn't running quite as fast as I'd like (although much faster than the 5400rpm HDD the laptop came with). It's rated at 3500 MB/s sequential read, 2500 MB/s sequential writes according to the Samsung website, but my benchmark tests using Samsung Magician have it running at 1739 MB/s sequential read and 1682 MB/s sequential write.

I think the problem is that according to both Samsung Magician and HWiNFO64, the PCIe slot the SSD is connected to is only running at x2. Frustratingly according to HWiNFO64, the maximum link width is 4x, but the current link width is 2x.

I've updated the BIOS to the most recent version F.04, but I don't see any options there to assign PCIe lanes. I've tried seating the SSD more firmly in the M.2 slot, and also removed the HDD in case the SATA controller was stealing a PCIe lane. It's still only at x2. Any other ideas?

The motherboard is 84A6, and the chipset is "Intel Kaby Lake-U + iHDCP 2.2 Premium PCH". I think this means 12 PCIe lanes for the CPU, and 24 lanes on the chipset, but really have no idea - couldn't find anything on specs for the motherboard. The HP spare parts number is L20371-601 if that helps.

[Huffer · Accepted solution]

There is really no way to alter the PCIe lane assignments. There is nothing in the Service Manual indicating if the M.2 slot is an x2 or an x4 slot. 

See p. 91:

Specs

Try running Sysoftware Sandra Lite (free download) to get detailed specs on your PCIe Bus. This is my Zbook 15 G3 which has a pair of NVME M.2 slots:

NVME slot on PCIe bus

The speeds you are getting are actually very good. These are my benchmarks using an older NVME M.2 disk:

Samsung PM951

[TC326]

Your hard drive is performing up to the specs listed for it at this site, but mine is not.

HWiNFO64 said it's an x4 slot, running at x2. I downloaded SiSoftware Sandra Lite 2018.8.28.26 and got the following (sorry, not sure how to post screenshots yet - I'm new to Windows):

System Bus 3

Type: PCIe 3.0 x2 8GBps

Multiplier: 3x

Bridge: Intel Sunrise Point-LP PCI Express Root Port #9

Device Connected: Samsung NVMe SSD Controller SM981/PM981

But then down below, there are "Performance Enhancing Tips":

Warning 1204: Link speed lower than maximum supported. Device may be in low-power mode.

Warning 1207: Link width lower than maximum supported. Device may be in low-power mode.

I guess the question is, how do I get it out of low-power mode?

[Huffer]

Check the overall power state and be sure you have everything set to best performance. Just left click the battery icon and there is a slider that will let you set it to best performance when plugged in or on battery. 

[TC326]

I've changed the power plan to max performance, and turned off "Link State Power Management" in the advanced settings, but still I get x2 only according to Samsung Magician, and Sandra says "PCI Express: Link State Power Management" is still on "maximum power savings" in the Power Management window. I can change it to "moderate power savings", but apparently the "off" option doesn't work.

Well, I guess I'm ok with x2. It still makes this machine a great deal, and probably way overpowered for my kid. And I can use this SSD someday (at x4!) if and when I upgrade my own computer. Thanks for your help. 

[citynomad1]

I noticed that your question was about the same (or very similar) laptop model to the one I have, using the same motherboard (84A6).  I also installed an NVMe drive (ADATA XPG SX6000) into mine.  I noticed that my NVMe drive runs quite hot (60-70C under normal operation, up to 80C under load).  I know that the excessive heat issue is a problem common to most (all?) NVMe drives, but in this particular laptop model it's exacerbated by very poor air circulation.  Have you had these issues with your drive, and if so, how did you solve it?

Also, have you been able to find a motherboard diagram/manual for this model?

Thanks.

[TC326]

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@citynomad1 wrote:

I noticed that your question was about the same (or very similar) laptop model to the one I have, using the same motherboard (84A6).  I also installed an NVMe drive (ADATA XPG SX6000) into mine.  I noticed that my NVMe drive runs quite hot (60-70C under normal operation, up to 80C under load).  I know that the excessive heat issue is a problem common to most (all?) NVMe drives, but in this particular laptop model it's exacerbated by very poor air circulation.  Have you had these issues with your drive, and if so, how did you solve it?

Also, have you been able to find a motherboard diagram/manual for this model?

Thanks.

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My drive never throttled itself that I could tell. It was usually running 60-70C, but after I took the HDD out, it is running more like high 50's to mid 60's C. Never found a motherboard diagram or manual.

[citynomad1]

Thanks.  Mine was throttling really badly before I installed a heatsink.  With a heatsink the performance has improved considerably - it doesn't seem to throttle anymore, but it still runs hot.  One of the reasons I wanted to find a motherboard diagram is that I was considering buying a heatsink with a fan (e.g. this one), and I wanted to see if there a spare 5v power connector somewhere on the motherboard to plug the fan in.