4090 Laptop GPU Working at Pcie GEN3 x8 instead of GEN4 x16

[lunimater]

Hi. I recently realized that my gpu is running at GEN3 x8 bus interface instead of GEN4 x16, and I couldn't find any information for this problem, at least regarding for laptops.

You can see from the Bus Interface, it shows PCIe x16 4.0 "at" x8 3.0, there is a game open in the background (at 3440x1440 resolution, and it is an UNREAL ENGINE 4 game, not a light game). I get stutters frequently on high demanding games including the one that is open in the background, and without an upscaling mod, I continue to get stutters often.

On HW Info software, it shows like this:

Also here is another one from CPU-Z:

I tried looking for a custom bios such as smokeless UMAF to see whether I can manually change PCIE speed or not but no luck. Is there any other way to fix this issue? My laptop comes with one nvme slot only.

Thank you!

 

[ir_cow]

Your not losing any performance with a laptop 4090 at 8x. Game shuttering is not because your at 8x

 

[lunimater]

Your not losing any performance with a laptop 4090 at 8x.

Hi, thank you for your answer. I know one or two things about differences between gen 4 x8 and x16, but the part worries me is when I open a game, after I start playing it, on GPU-Z, it shows my gpu working at x8 3.0(gen 3). Should I disregard what it shows on GPU-Z too? It shows 3.0 only with GPU Z software, other apps showing x8 without specifying whether it is 3.0 or 4.0.

 

[ir_cow]

Hmmm I would trust GPUz. I was thinking my just in terms of gen4 16x vs 8x.

Have you tried the load function? (Press the ?). It will show you what it's running at under load.

Maybe someone else knows why it's going to Gen3 8x.

 

[lunimater]

It is turning itself to x8 3.0. After I stop the render test, it goes back to x8 4.0, it is weird.

 

[gffermari]

Check the laptop's specs for details.
If you got 2 (or more) nvme drives, the mb may cut lanes from the PCIe.

 

[lunimater]

Hmmm I would trust GPUz. I was thinking my just in terms of gen4 16x vs 8x.

Have you tried the load function? (Press the ?). It will show you what it's running at under load.

Maybe someone else knows why it's going to Gen3 8x.

Check the laptop's specs for details.
If you got 2 (or more) nvme drives, the mb may cut lanes from the PCIe.

Okay, I believe I figured it out. It might sounds silly but here is what I found:

I also did a benchmark test and the result came out ridiculously low. I use an external monitor, and it seems, the monitor itself was causing x8 3.0 speeds, basically, after I pull off external monitor and restart my laptop, I did another test and the result came out as it supposed to be. So an inferior external monitor or HDMI cable being used affect the pcie speeds. It looks like I have to buy a new HDMI cable for my monitor. That's all. Still, thank you for writing under this thread.