14900 or mobo issue with nvme?

[LGabrielPhoto]

Hi.
I have an issue with the top nvme slot. Any nvme I use on that top slot, the speed drops to half.
So my drives that normallly run at 7000, only deliver 3500 on that top slot
And my older drive that maxes out at 3500, on that top slot it just hits 1700s.

I thought maybe it was the 4090 taking all the bandwidth but even if I remove the 4090, reinstall windows and only use the igpu from the 14900k, the issue still happens..
Is an asus proart z790 with 1801 latest bios.
Any thoughts?

 

[Dopamin3]

I thought maybe it was the 4090 taking all the bandwidth but even if I remove the 4090, reinstall windows and only use the igpu from the 14900k, the issue still happens..

No, that would not fix it. The top NVME doesn't share bandwidth with any other connectors.

Given you've tried both Gen3 and Gen4 drives and the speed is halved- it sounds like the NVME slot is running at x2 Gen3 or x2 Gen4. You can check CrystalDiskInfo and look at Transfer Mode to verify this.

I would start in the BIOS and force the speed to Gen4 on the top NVME slot and see if you get PCIe 4.0 x4. If you still don't then re-situate the CPU in the socket.

 

[LGabrielPhoto]

No, that would not fix it. The top NVME doesn't share bandwidth with any other connectors.
View attachment 622826

Given you've tried both Gen3 and Gen4 drives and the speed is halved- it sounds like the NVME slot is running at x2 Gen3 or x2 Gen4. You can check CrystalDiskInfo and look at Transfer Mode to verify this.
View attachment 622828

I would start in the BIOS and force the speed to Gen4 on the top NVME slot and see if you get PCIe 4.0 x4. If you still don't then re-situate the CPU in the socket.

So odd.
Forced it to 4 and windows can see it but cannot copy or do anything with it.
Changed it to 3 and it boots fine but the speed is only like 1800s.
Set it to Auto and the speed goes to 3500 (still way under 7000) and disk mark info shows as 4x2.0 when on Auto

 

[Dopamin3]

So odd.
Forced it to 4 and windows can see it but cannot copy or do anything with it.
Changed it to 3 and it boots fine but the speed is only like 1800s.
Set it to Auto and the speed goes to 3500 (still way under 7000) and disk mark info shows as 4x2.0 when on Auto

Odd indeed. That top slot is basically directly from the CPU and not the chipset. So it could be a messed up pin in the socket, weird mounting pressure from the heatsink (unlikely but I have seen it cause strange issues on older platforms), a faulty CPU, or a faulty motherboard (potential damaged tracing to the NVME). A re-seat of the CPU in the socket would still be my first go to and check the LGA pins.

 

[pendragon1]

does it get them same low speed in all three m2 spots? is its firmware up to date?

 

[LGabrielPhoto]

Just a final update.
I replaced the Mobo and all is good. All slots are running perfectly at full speeds.

 

[flegg]

WHENEVER you have an asus mobo you should just assume it is the culprit until proven otherwise

 

[LGabrielPhoto]

WHENEVER you have an asus mobo you should just assume it is the culprit until proven otherwise

considering of all the Asus mobos this is the first one that has such issue AND it was an open box from Newegg, that is an absurd claim.