Graphics card PCIe x8 running at x1

As the title (sort of) states, I have a problem whereby my nVidia graphics card is being forced to run at a PCIe speed of x1 even though it's a x8 card.

It's a Dell Optiplex 755 Mini Tower (specs should be here somewhere). The PCIe slot on my PC should be a PCIe 2.0 slot from what I could find out on the internet.

I've run various pieces of software, including CPU-Z, GPU-Z, Speccy and AIDA64. They all report the PCI Express slot as a 1.1 slot. However, nVidia Inspector reports the slot as a 2.0 slot. Not sure why.

On top of that, the software (not nVidia Inspector) all report the card to be running at x1, though the card is a x8.

I'll attach a screenie of GPU-Z, and you can see what it says about the PCIe status.




The PCI Express slot should be 2.0 as far as I can tell, and according to nVidia Inspector. But I have no clue as to why all other software seem to say it's only 1.1. I assume this is why it's running at x1 and not x8 as it should be, and the slot is x16.

The BIOS revision on the PC is up to date as well, and there are no BIOS options to alter the way the PCI Express works.

Um... any ideas anyone?

@RoasterMan - I am using the x16 slot. It's the only PCIe slot on the board, other than the PCIe x1 slot.

@AddRAM - I didn't run it fullscreen, no. I assume you mean the render test in GPU-Z? I only ran it in the small window it starts in.

@ThrashZone - I only have the one full size PCIe slot on this motherboard, two normal PCI slots and a small PCIe x1 slot. The slot is also at the top of the top of board, as these Dells have their motherboards upside down and back to front. In other words, it's in the only slot it will fit in :)

@AddRAM - I can't take a photo at this moment, but I can at least link you to the exact motherboard my Optiplex has: Dell Optiplex 755 "GM819"

Apparently it's a GM819. That's all I can locate on the board, and that it's manufactured by Foxconn. It's definitely inserted into the x16 slot as it's the only slot there. I've been unable to find any solid information from Dell regarding the actual speed of these PCIe slots.

Try reseating the card. I have seen cards not running properly (x8 vs x16, etc.) be corrected by reseating. Might be dirty contact or slight misalignment.

Well I did get a pop up mentioning a full screen render test, but it said it was used for such things as SLi / multi GPU setups.