Question PC runs at PCIe x2 on some bootups

[taito1]

Built a new pc over the weekend and everything seems to be working fine and normal. But sometimes when I check GPU-Z my GPU "bus interface" seems to be running at "x2 4.0" even though it's capable of running "x16 4.0", it seems to be down to luck whether my pc boots up with x16 bus interface or if it boots up with x2.

I tried clicking the little "?" on GPU-Z to open up the gif/video, I refresh GPU-Z and it's still running at x2.

I have seen people mention that GPU-Z can be wrong at times, but I still notice a massive difference in FPS and sometimes even micro-stutters, which is usually my cue to check GPU-Z to see if the bus interface is messed up again. (which it usually is)

One more thing to note is that my 3DMark score seems to be 900-1300 points below the average benchmarks.

I have tried the following: reseating RAM, reseating and cleaning the golden pins on the GPU, checking CPU socket for bent pins, setting PCIe to "Gen4" instead of "Auto" in the BIOS.

I am not very tech-savvy, so hopefully everything looks good on GPU-Z:

 

[rgd1101]

full system spec?

 

[taito1]

full system spec?

MSI B650 Gaming Plus wifi
7800X3D
Gskill trident 32gb
RM1200x
MSI 4080 Super​

 

[taito1]

I tried my old 1080 and that was running at x16 even after 9 restarts, I'm starting to think that the GPU is somehow messed up.

I also tried switching the GPU from "silent mode" to "gaming mode", hopefully this is the solution

 

[rgd1101]

latest motherboard bios?

 

[Satan-IR]

That's most probably because of Windows and Graphic Card power optimization settings. The card clocks down when it's idle, to save energy.

When you open GPUZ it clocks the GPU and VRAM up for a second to it shows the maximum. Then it goes down.

You see that question mark next to the Bus Interface box where it shows it was running at 16x 4.0 when you took the screenshot? Click that and a render test box will pop open. Then click the Sart Render Test and that would clock the GPU/VRAM up and in the Graphics Card tab the Bus Interface will show the proper PCIE revision/version.

 

[taito1]

latest motherboard bios?

Yeah I'm currently running latest bios

 

[taito1]

That's most probably because of Windows and Graphic Card power optimization settings. The card clocks down when it's idle, to save energy.

When you open GPUZ it clocks the GPU and VRAM up for a second to it shows the maximum. Then it goes down.

You see that question mark next to the Bus Interface box where it shows it was running at 16x 4.0 when you took the screenshot? Click that and a render test box will pop open. Then click the Sart Render Test and that would clock the GPU/VRAM up and in the Graphics Card tab the Bus Interface will show the proper PCIE revision/version.

The render test doesn't budge the bus interface, neither does running a game.
If it's on x1, it'll be stuck on x1 until I restart the PC.

Also noticed that whenever it does run at x1 or x2, my FPS drops by like 90-180

 

[Satan-IR]

The render test doesn't budge the bus interface, neither does running a game.
If it's on x1, it'll be stuck on x1 until I restart the PC.

Also noticed that whenever it does run at x1 or x2, my FPS drops by like 90-180

That's really odd. I haven't seen it happen with a graphics card/system like this.

You said you have latest BIOS installed on motherboard. Maybe a CMOS reset to default values would help.

Might be something firmware related on the graphics card (cause they have their own BIOS). Negotiating the highest possible speed on a PCIe host controller is kind of the task any BIOS/board should be able to do unless there is some flaw or glitch in the design or a bug the firmware (BIOS) forcing a lower speed on the host controllers. This appears to be intermittent on your system.

 

[taito1]

That's really odd. I haven't seen it happen with a graphics card/system like this.

You said you have latest BIOS installed on motherboard. Maybe a CMOS reset to default values would help.

Might be something firmware related on the graphics card (cause they have their own BIOS). Negotiating the highest possible speed on a PCIe host controller is kind of the task any BIOS/board should be able to do unless there is some flaw or glitch in the design or a bug the firmware (BIOS) forcing a lower speed on the host controllers. This appears to be intermittent on your system.

I agree, it's very strange how the BIOS won't allow me to set the PCI to x16 lanes manually.

Maybe I just keep waiting for BIOS updates and/or nvidia drivers that might fix this bug/issue.

On a brighter note though, flicking the physical switch from "silent" to "gaming" on the GPU seems to have fixed the issue (knock on wood) the GPU has been consistently running on x16 PCIe now even after multiple reboots!
It's either that or my old GPU somehow fixed the PCIe slot