NVMe drive can't boot in 4x mode

[Gostop]

Hey everyone,

 

CPU: I7 4790k

MOBO: Asus z97 Sabertooth Mk.2 (Lastest firmware)

GPU: 980 ti

RAM: 16gb ddr3 corsair domninator 1866

Storage:

C:/ - Samsung PRO NVMe on Silverstone PCIe M.2 Expansion card. 

D:/ - Crucial MX SSD 500gb x2 Raid 0 

E:/ - WD Red 2TB x2 Raid 0 

 

My issue is that if my computer powers off, it always boots into bios and does not detect the NVMe drive. However, if I switch the drive from 4x mode to 2x mode after a shutdown/restart... the drive suddenly works!

 

I should clarify that this works in vice versa as well. So if the PC shuts down in 2x mode, and I boot it back up, it goes back into bios and switch it to 4x mode... it once again detects the drive when I save to bios and exit.

[paddy-stone]

Can you save a profile on your mobo? if you can at least that will save you having to chnage settings each time... you could then load your profile and save on exit instead, at least that would save a few steps.

[Dabombinable]

4 minutes ago, Gostop said:

Hey everyone,

 

CPU: I7 4790k

MOBO: Asus z97 Sabertooth Mk.2 (Lastest firmware)

GPU: 980 ti

RAM: 16gb ddr3 corsair domninator 1866

Storage:

C:/ - Samsung PRO NVMe on Silverstone PCIe M.2 Expansion card. 

D:/ - Crucial MX SSD 500gb x2 Raid 0 

E:/ - WD Red 2TB x2 Raid 0 

 

My issue is that if my computer powers off, it always boots into bios and does not detect the NVMe drive. However, if I switch the drive from 4x mode to 2x mode after a shutdown/restart... the drive suddenly works!

 

I should clarify that this works in vice versa as well. So if the PC shuts down in 2x mode, and I boot it back up, it goes back into bios and switch it to 4x mode... it once again detects the drive when I save to bios and exit.

Is it in the bottom "x16" slot? I recently found out from the manual that you actually have to disable the rear USB 3.0 "E1-E2" ports to get it to run at x4 instead of x2 (I've got the same motherboard, plus I keep its manual in the side of the case)

[0x1e]

4 hours ago, Dabombinable said:

Is it in the bottom "x16" slot? I recently found out from the manual that you actually have to disable the rear USB 3.0 "E1-E2" ports to get it to run at x4 instead of x2 (I've got the same motherboard, plus I keep its manual in the side of the case)

All the USB 3.0 ports should disable, and the second x1 pci-e slot automatically if you enable the last pci-e slot to x4.

[Dabombinable]

50 minutes ago, 0x1e said:

All the USB 3.0 ports should disable, and the second x1 pci-e slot automatically if you enable the last pci-e slot to x4.

Going off the manual, its only the rear USB 3.0 ports that get disabled-unlike my old H87M Pro, it had both PCIEx1 slots (and therefore my wifi & IDE adapter cards) disabled to run the bottom slot at x4.

[Gostop]

Ok, so I tried disabling the USB 3.0 ports 1 and 2. Still having the same issue as described.

 

PCI-e lanes are as follows

 

sound card (x1)

980 ti (16x)

open (x1)

980 ti (16x)

open (x1)

SSD (x4)

[Gostop]

17 hours ago, Dabombinable said:

Going off the manual, its only the rear USB 3.0 ports that get disabled-unlike my old H87M Pro, it had both PCIEx1 slots (and therefore my wifi & IDE adapter cards) disabled to run the bottom slot at x4.

Hey, was just reading online while at work.

 

So the bottom lane is only PCIe 2.0 and the Samsung PRO 950 is based off of PCIe 3.0 protocol. Think this might cause it to not detect it as a boot drive on power/restart? 

 

People are saying the performance should be hindered but when I run the benchmark with the SSD in that PCIe 2.0 lane I get 1800+ in 4x mode in comparison to the 800 in x2 mode.

 

Ill try it when I get home.

[Dabombinable]

8 minutes ago, Gostop said:

Hey, was just reading online while at work.

 

So the bottom lane is only PCIe 2.0 and the Samsung PRO 950 is based off of PCIe 3.0 protocol. Think this might cause it to not detect it as a boot drive on power/restart? 

 

People are saying the performance should be hindered but when I run the benchmark with the SSD in that PCIe 2.0 lane I get 1800+ in 4x mode in comparison to the 800 in x2 mode.

 

Ill try it when I get home.

It should run just fine, but at half the theoretical speed. On my H87M Pro (never needed to try on my Z97 Sabertooth) I had no troubles running a GTX 650ti 2GB as a PhysX card off the x4 slot-and in fact it worked perfectly, with my GTX 970 seeing a noticeable boost in games with PhysX (though with some of them being old, I was running 4x 1080p DSR). I was running the GTX 650ti with a 120MHz overclock, and my GTX 970 at stock BTW.

[Gostop]

1 hour ago, Dabombinable said:

It should run just fine, but at half the theoretical speed. On my H87M Pro (never needed to try on my Z97 Sabertooth) I had no troubles running a GTX 650ti 2GB as a PhysX card off the x4 slot-and in fact it worked perfectly, with my GTX 970 seeing a noticeable boost in games with PhysX (though with some of them being old, I was running 4x 1080p DSR). I was running the GTX 650ti with a 120MHz overclock, and my GTX 970 at stock BTW.

Ah I see,

 

Well there seems to be some architectural issues that keep the drive from telling the machine that it's bootable when you are in PCIe 2.0 lane. I switched to the second 3.0 lane and boom, works like a charm. No improvement on speed though, oddly enough.

 

Looks like I have a choice to make here,

 

I can upgrade my video card in the future and just run 1 980 Ti, or change to the X99 platform to accommodate my PCIe usage.

[Dabombinable]

14 minutes ago, Gostop said:

Ah I see,

 

Well there seems to be some architectural issues that keep the drive from telling the machine that it's bootable when you are in PCIe 2.0 lane. I switched to the second 3.0 lane and boom, works like a charm. No improvement on speed though, oddly enough.

 

Looks like I have a choice to make here,

 

I can upgrade my video card in the future and just run 1 980 Ti, or change to the X99 platform to accommodate my PCIe usage.

If that's the results, it might be worth contacting Asus as its clearly the BIOS that is limiting which slots can handle NVME. And now I'm having even more second thoughts about the decision to go with GTX 970 SLI-I was hopping to switch to an NVME boot SSD at the same time due to my current OCZ Arc 100 240GB wearing out rapidly (it has far lower maximum daily writes than my 2011/2012 Sandisk U100 and 2015 Kingston SSDNow V300)

[samiscool51]

the Silverstone PCIe M.2 Expansion card might not support 4x mode with the Samsung PRO NVMe, sometime you just have weird problems that don't happen if you use the integrated m.2 connector on an mb

after googling for 2-3 mins, this turned up

https://arstechnica.com/civis/viewtopic.php?f=8&t=1252823

Quote

And I stumbled upon something I didn't know was possible: the M.2 connector on the Asus Z97-A works only in the PCIe mode, which renders it incompatible with many M.2 drives

 i think the same is happening to you as well as you can't boot in 4x mode

[Dabombinable]

27 minutes ago, samiscool51 said:

the Silverstone PCIe M.2 Expansion card might not support 4x mode with the Samsung PRO NVMe, sometime you just have weird problems that don't happen if you use the integrated m.2 connector on an mb

after googling for 2-3 mins, this turned up

https://arstechnica.com/civis/viewtopic.php?f=8&t=1252823

 i think the same is happening to you as well as you can't boot in 4x mode

It seems to be working correctly. As far as I understand, in the PCIe 2.0  "x16" slot (really x2-4)it won't boot when set to x4, but it will at x2. And when used in the 2nd PCIe 3.0 x16 slot, it works as it should. So its definitely compatible, the motherboard just doesn't like NVME drives used with the bottom slot when its set to x4. Unless its because of the motherboards design, its the type of issue that Asus could solve with a BIOS update. Especially since there isn't a speed increase with the SSD going from PCIe 2.0 x4 (2GB/sec) to 3.0x4 (4GB/sec)

[Gostop]

1 hour ago, samiscool51 said:

the Silverstone PCIe M.2 Expansion card might not support 4x mode with the Samsung PRO NVMe, sometime you just have weird problems that don't happen if you use the integrated m.2 connector on an mb

after googling for 2-3 mins, this turned up

https://arstechnica.com/civis/viewtopic.php?f=8&t=1252823

 i think the same is happening to you as well as you can't boot in 4x mode

Ah I see,

 

Not the issue I am having I am afraid, but I think that my motherboard (ASUS z97 Saberooth MK 2) does not come with an m.2 slot. My current bios revision is 2702. The boards compatibility with NVMe drives came with a bios update from reading the update history. Which also leads me to back up @Dabombinable in his suggestion of a bios update. I am not sure how to get the ball rolling on this or how to even suggest it in the first place to ASUS though. 

 

So right now my system is running on one less graphics card, which really is fine for my use case thankfully. This rig can survive on a single 980 Ti. I can just sell it, and upgrade my HTPC rig which does all the heavy lifting for graphic intense gaming. 

[Dabombinable]

1 hour ago, Gostop said:

Ah I see,

 

Not the issue I am having I am afraid, but I think that my motherboard (ASUS z97 Saberooth MK 2) does not come with an m.2 slot. My current bios revision is 2702. The boards compatibility with NVMe drives came with a bios update from reading the update history. Which also leads me to back up @Dabombinable in his suggestion of a bios update. I am not sure how to get the ball rolling on this or how to even suggest it in the first place to ASUS though. 

 

So right now my system is running on one less graphics card, which really is fine for my use case thankfully. This rig can survive on a single 980 Ti. I can just sell it, and upgrade my HTPC rig which does all the heavy lifting for graphic intense gaming. 

Even with the last BIOS version you'll probably have the same issue-which is why I suggest contacting Asus. Because they are the only ones who will be able to do anything-and we already know that with some NVME SSD, the bottom PCIe 2.0 slot doesn't impact performance.