Inspiron 5675, motherboard PCIe slots?

Thanks for the info, but this does not answer which slot supports PCIe 3.0 x8 and PCIe 3.0 x16.

Simplest solution is to move your video card to the other x16 slot and see if it runs at X16 now.  

Typically, the one closest to the CPU is x16. The motherboard might have it labeled by each slot. GPUz will show it in the "Bus Interface" section.

Changing slots would require my to knock out the covers on the back of the PC and re-route some of the power supply cables. Why can't Dell answer this question? Here is what GPU-Z shows:

PCIE X16 3.0 @ X8 3.0

It looks like the slot Dell put the card in doesn't support this video card, or something else in the computer is using the resources.

Based on GPU-Z, that PCIe x16 slot is operating at x8 with that video card.

The Owner's Manual page 84 shows this easy process to remove the video card and insert it into the other PCIe x16 slot. Then run GPU-Z and see what it states.

* Turn the computer off
* Disconnect the power cable from the computer
* Disconnect the monitor from the video card
* Remove the two screws from the black video card bracket

* Remove the two screws holding the video card
* Push the securing tab on the PCIe x16 slot away from the graphics card, grasp the card by its top corner, and ease it out of the slot

* Remove the back slot cover (it just slides up and out)
* Install the video card in the other PCIe x16 slot
* Affix the two screws holding the video card
* Reconnect the black video card bracket
* Attach the monitor to the video card
* Reconnect the power cable to the computer
* Power on. Run GPU-Z and post the result for us

Does your video card 'down-clock' automatically when it's not running at full load?

Do you have the latest versions of BIOS (1.3.4;  "Enhanced user experience for online games and video playback"), AMD chipset, and AMD video driver and AMD video controller?

Yes, at no load GPU-Z shows 'PCIE X16 3.0 @ X8 1.1' at full load using FurMark, GPU-Z shows PCIE X16 3.0 @ X8 3.0. It appears to be loading to a higher bus speed at x8 only. I am thinking about moving the video card to the other slot, but want to make sure there isn't another problem first. I don't want to knock out the slot blanks in back of the case to move the video card and I would also have to re-route some power supply cables to move the video card. I do have a supportcase open with Dell and they are supposed to be working on it, I am waiting to see result.

I do have the latest bios 1.3.4

[edited 11/16: corrected typos]

I can confirm what krking111 has observed.  

I'm currently on BIOS 1.3.4:

580 is in slot 1 - I'm seeing it reported at card reports that it supports 16x 3.0, however it shows 8x 3.0 when running GPU-Z Render Test.

I have swapped to PCIe 16x slot 2 with the same results:

showing 8x 3.0 when running the GPU-Z Render Test.

Please, please tell me this is just a bios issue...and not a marketing SNAFU where physically the slots are 16x but are really wired electrically as 8x.

On a related note, I was even prepared to move the SSD to the other slot to see if it was something strange like the 16x slot 1 was sharing PCIe lanes with it.  However, I figured this possibility is out after moving the card to slot 2 and seeing the same issue.

Any help/suggestions/clarifications from Dell would be much appreciated.  I would hate to see this situation get out of control if Dell can't/won't get out in front of the issue and officially address the concerns.

Don't get me wrong, I really do like the 5675, but seeing something advertised as one thing, and not seeing it once you've purchased can really affect customer loyalty.

Incidentally, I've tested a 7775 AIO and its GPU is reported at 16x.

Thanks and hopefully we can get someone to address this.

Driver version 23.20.788.0

I have an open case with Dell level 3 support and am waiting for their response. I'll update as soon as I hear from them. Everything on my computer has been updated including windows 10 and verified by Dell support.

You said there's an 580X video card installed.

Look in Device Manager and find the version number of the driver that's running this card and post it here...

krking111, wc808,

Please run GPU-Z again. Post a screenshot of the GPU-Z screen showing "x8". Also post a screenshot of the AMD Radeon application hardware tab showing "x8".

Here is the info