X299-A + NVME SSD Read Speeds

ZXSpectrum · 13 Jul 2017 at 16:21

Does anyone have this motherboard with a NVME SSD? I am currently working with Asus trying to sort an issue out with NVME SSD Speeds. Basically when the SSD is tested using Atto I am getting over 400mb/sec lower performance than I get with these SSDs in a X99 system. I have so far tried 1Tb SM961, 500Gb 960 Evo and I am just about to test a 400Gb Intel 750 series.

Does anyone have similar issues?

ZXSpectrum · 15 Sep 2017 at 14:54

Just to update this thread... I am still no closer to a resolution on this matter. I am surprised that no one else has experienced the same issues as currently it happens on the X299-A and the X299-TUF MK2 with the Samsung drives.

Orcvader · 15 Sep 2017 at 16:38

What was the X99 board that you tested with? What sort of speeds are you getting exactly?

ZXSpectrum · 18 Sep 2017 at 16:29

I have tested an X99-E WS and this is the speed I usually get from these drives on that motherboard. I have checked this against test reports on about 20 systems.

Advertised speed of drive: 3200MB/s Read - 1800MBs Write

X99 Speeds - 3079MB/s Read - 1819MB/s Write
Z170 Speeds - 3101MB/s Read - 1764MB/s Write
Z270 Speeds - 3081MB/s Read - 1806MB/s Write

X299 Speeds - 2578MB/s Read - 1801MB/s Write

It is not the write speeds that are the issue but the read speeds are about 20% down on other Intel based chipsets.

Asus are currently (Well have been for over 2 months now) looking into the issue and in contact with Intel regarding the issue. Asus sent me their latest bios for the X299-A boards but there was no significant change in speed.

Orcvader · 18 Sep 2017 at 17:29

That does seem a bit strange. Another thing that could come into play... what temps is the SSD reaching?

Although with the Prime X999-A the heatsink should actually be helping with thermal throttling.

Do you know which chip is controlling the PCIe lanes? Both the CPU and chipset provides PCIe 3.0 but the manual doesn't state which one the NVME slot is hooked up to, although I suspect it could be the chipset. X99 is most likely from the CPU directly as the X99 chipset only provided PCIe 2.0. The Z170 seems to provide PCIe 3.0 lanes as well but this is the "midrange" platform so the SSD may be hooked to the CPU directly too.

ZXSpectrum · 19 Sep 2017 at 09:10

I believe the PCIe lanes are directly from the CPU rather than the PCH. But, I have also tried in a PCIe adapter so that would negate the issue with the m.2 slots.

Temps are fine with the heatsink applied it doesn't really get above 50 degrees.

Orcvader · 19 Sep 2017 at 12:42

Using the PCIe adapter, which PCIe slots did you try?

This cropped up on Reddit today and seems to suggest trying to use lanes directly from the CPU won't work, although that could be for booting only.

ZXSpectrum · 20 Sep 2017 at 09:33

I tried all the available slots with the PCIe adapter. I have also tried both the M.2 slots.

ZXSpectrum · 20 Sep 2017 at 13:18

I have now had some information back from Asus stating that apparently its a limitation of the X299 chipset and all motherboard manufacturers are experiencing the same issues.

I have been told that you do have to use a pcie slot that is directly connected to the CPU rather than the PCH (I am certain I tried this already) but I will test the theory shortly.

ZXSpectrum · 20 Sep 2017 at 14:58

And after testing.. Well it looks like Asus are correct. It looks like you cannot run a M.2 PCIe NVME drive from the M.2 slots onboard at their full speed. While I understand that most people will never notice this issue and their drive would still be silly fast but apparently to get 100% performance of your M.2 Drive on X299 platform you HAVE to use a M.2 - PCIe adapter and ensure that you are using a slot that utilises PCIe lanes that are from the CPU not the PCH.

Apparently this is a limitation with the X299 chipset but to be honest it sounds more like an architecture fault. You cannot use the onboard M.2 slots to get full speed and have to take up an additional PCIe slot and purchase a M.2 - PCIe adapter to get the full speed of your NVMe SSD.

HoneyBadger · 20 Sep 2017 at 15:22

That sounds utterly ridiculous!

I would return it if it were me. False advertising.

gary996 · 20 Sep 2017 at 16:51

me 2 I would return the lot and switch to Ryzen. Seems like x299 is having problems

ZXSpectrum · 20 Sep 2017 at 18:12

lol I know, it's dev/diagnostics I am doing currently. Good job as if it was me I would have ditched it. And I have direct access to Asus technical and loads of components so god knows how anyone at home would be able to diagnose...

Orcvader · 22 Sep 2017 at 22:08

Having a look the X299 is hooked up to the CPU via DMI 3.0, which itself has 4 lanes transferring at 8 GT/s each. This matches PCIe x4 for roughly ~3.94GB/s but looking at your SSD's advetised speeds it shouldn't be saturating this, unless the CPU/chipset is throttling it to ensure it doesn't affect the other things connected to the chipset.

B22222C · 8 Jan 2018 at 23:48

Same with Asus Strix XE Gaming motherboard... Using Samsung 960 Pro and get speeds of 1800/1600... Instead of something around 3500/2500...
I will buy a m.2 pcie adaptor and i expect to get much higher speeds...
As anyone try to play with bios settings and try to alocate more lanes to m.2 slot or something else?

B22222C · 10 Jan 2018 at 16:30

Issue fixed with an m.2 Adaptor...
I use Asus Hyper M.2 X4 Mini and i get speeds of 3150/2050...
My motherboard is Asus Strix XE Gaming and 7820X processor and my M.2 disk is Samsung 960 Pro!

ZXSpectrum · 11 Jan 2018 at 09:10

Yeah its because both of the onboard M.2 go via the PCH. If you use an adapter you can use one of the slots that go directly to the CPU. Still stupid that to get the correct speeds out of the Nvme drives you have to take up a PCIe slot and not use the onboard ones.

FredFlint · 12 Jan 2018 at 01:48

ASUS should have used lanes from the CPU for the M.2 ports, that's what they did on X99. They blame the chipset but they made the mobo and they knew it only had 4 lanes from the PCH to the CPU.

Chaos666 · 21 Jan 2018 at 00:51

So how come x99 was able to use pci lanes straight from the cpu and x299 us not.... Design flaw? They've rushed the launch of x299
I can reach 3500 read on my ****** msi x99

P. S: hello from Derby zxspectrum

sithlord · 21 Jan 2018 at 13:12

Arent the CPU lanes dictated by the CPU ? 16 lanes or 28 lanes or 44 lanes depending on the CPU.

I know on my SLI PLUS I got full speeds from my NVMe at 2,900MB/s read and that was with 6 of the sata ports occupied.