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M.2 Issue, half speed on M.2.1, Full speed on M.2.2

wolfman
Level 7
As the title suggests, I'm having an issue with my M.2 slots using a samsung 970 EVO plus nvme 1TB drive. I should also tell you that this drive is replacing a Samsung 960 EVO nvme 500GB drive that showed the same issue.

When I test the speed in the M.2.1 slot, located near the bottom of MB, my speed on Crystal disk mark 7 is 1802 read, 1813 write. When I use the M.2.2 slot, located near the CPU, I get the following results, 3268 read, 2880 write.

I am using the latest BIOS, 3004 from Asus. My MB is Asus ROG Crosshair VII Hero WIFi, CPU is a Ryzen 2700+, 16 Gb DDR4 3200RAM, windows 10.

I'm just wondering why the speed is basically cut in half using the M.2.1 slot. I have reset the BIOS to default and nothing works as far as getting full speed on the M.2.1 slot.

Any suggestions?
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17 REPLIES 17

davemon50
Level 11

davemon50 wrote:
Looks familiar. This you?
https://rog.asus.com/forum/showthread.php?115965-M-2_1-slow-speed&highlight=samsung


No, not me, but I'll look it over and see if it will help. At least I'm not crazy and someone else has had the issue.

davemon50
Level 11
Sounds exactly the same.
Davemon50

As I stated the first time you asked me, that is not my post.

I'm just looking for some assistance on the issue that I'm having.

davemon50
Level 11
Yes I know that. Agreeing that the issue sounds exactly the same, not calling you a liar. 😉


Did the other thread help you or no? You never reported back.
Davemon50

Finally got some time to do a secure erase from BIOS and then did a restore with Macrium and same result. Faster on the M.2.2 than M.2.1. I even did a fresh install of Windows 10, installed all the MB drivers, etc., samsung NVME driver and same result on a fresh Windows 10 install, faster on M.2.2 than M.2.1.

It's not an OS issue, I've been over the BIOS settings again and again looking to see If I've missed anything, and I am at a loss to explain this.

Baio73
Level 8
wolfman wrote:
As the title suggests, I'm having an issue with my M.2 slots using a samsung 970 EVO plus nvme 1TB drive. I should also tell you that this drive is replacing a Samsung 960 EVO nvme 500GB drive that showed the same issue.

When I test the speed in the M.2.1 slot, located near the bottom of MB, my speed on Crystal disk mark 7 is 1802 read, 1813 write. When I use the M.2.2 slot, located near the CPU, I get the following results, 3268 read, 2880 write.

I am using the latest BIOS, 3004 from Asus. My MB is Asus ROG Crosshair VII Hero WIFi, CPU is a Ryzen 2700+, 16 Gb DDR4 3200RAM, windows 10.

I'm just wondering why the speed is basically cut in half using the M.2.1 slot. I have reset the BIOS to default and nothing works as far as getting full speed on the M.2.1 slot.

Any suggestions?


Hi,
Asus made a little mess with this board* as they called the upper slot (the nearest to the CPU socket) M.2_2 and the bottom one M.2_1 (which is not so intuitive as the PCIEX slots are numbered starting from the upper one).
So the upper slot is the slower, as it shares ìlines with PCIEX slot 1 (where one usually plugs the VGA) and the bottom slot is the faster, as it does not share anything.
Hope this may help!

Baio

* I've just discovered that USB15 header can't drive 2 USB ports… so a topboard like this has only 3 onboard USB ports… WTF!!!
CASE Lian Li 011D XL CPU AMD Ryzen 7950X3D COOLER Corsair H150i Elite Capellix MOBO Asus ROG Strix X670E-A Gaming Wifi RAM 2x16Gb Corsair Dominator Titanium 6000 [CMP32GX5M2B6000Z30] PSU Asus Thor 1200P VGA Asus ROG Strix RX 6900XT DISPLAY LG 34GK950GF AUDIO Logitech G560 SDD NVMe WD Black SN850 4Tb INPUT Logitech Pro wireless + Powerplay + Corsair MM 700 RGB - Corsair K100

Baio73 wrote:
Hi,
Asus made a little mess with this board* as they called the upper slot (the nearest to the CPU socket) M.2_2 and the bottom one M.2_1 (which is not so intuitive as the PCIEX slots are numbered starting from the upper one).
So the upper slot is the slower, as it shares ìlines with PCIEX slot 1 (where one usually plugs the VGA) and the bottom slot is the faster, as it does not share anything.
Hope this may help!

Baio

* I've just discovered that USB15 header can't drive 2 USB ports… so a topboard like this has only 3 onboard USB ports… WTF!!!


Thanks for the reply. I understand the information regarding M.2.1 and M.2.2. My issue is that M.2.1 is HALF the speed of M.2.2. My 970 evo has a speed of 1802 read, 1813 write in the M.2.1 location and a speed of 3268 read, 2880 write in the M.2.2 location.

wolfman wrote:
Thanks for the reply. I understand the information regarding M.2.1 and M.2.2. My issue is that M.2.1 is HALF the speed of M.2.2. My 970 evo has a speed of 1802 read, 1813 write in the M.2.1 location and a speed of 3268 read, 2880 write in the M.2.2 location.


Sorry for the misunderstanding… you are the first user I read of to have the inverse problem.
Maybe a full list of your configuration may help, but for sure M.2_1 does not share anything with the rest of the system, so the problem is really misterious.
Did you try to open a ticket with Asus assistance?
Did you try the SSD in another pc to see what performance it has?
At the moment I can't think of anything else, apart for a BIOS flash using the flashback method.

Baio
CASE Lian Li 011D XL CPU AMD Ryzen 7950X3D COOLER Corsair H150i Elite Capellix MOBO Asus ROG Strix X670E-A Gaming Wifi RAM 2x16Gb Corsair Dominator Titanium 6000 [CMP32GX5M2B6000Z30] PSU Asus Thor 1200P VGA Asus ROG Strix RX 6900XT DISPLAY LG 34GK950GF AUDIO Logitech G560 SDD NVMe WD Black SN850 4Tb INPUT Logitech Pro wireless + Powerplay + Corsair MM 700 RGB - Corsair K100