lga775 PCIe bandwith problem

ChatDaw · May 3, 2016

Hi,

as the title already mentions, I have a PCIe bandwith issue with an old LGA 775 motherboard I currently use cause it's the only system I can really use at the moment.
The motherboard is an Asus P5KPL/1600 and has two PCIe slots, one 16x and one 4x according to Asus's website : https://www.asus.com/Motherboards/P5KPL1600/.

Two days ago, I tried fixing a Sapphire Radeon R7 250 which gives me black screens every now and then on a few different systems even if she's not under load.
To make that possible, I tried plugging it in the second PCIe slot, which starved my 9500GS at 1x speed and 4x for the R7. Weird IMHO.
It wasn't scary at first but then I saw Bus Interface usage peaking at a 100% in GPU-Z AND intermittent stuttering even when watching a YouTube video with the 9500GS I normally use in 16x.
After trying to fix the R7 card, without success, I decided to plug only my 9500GS back in and use this PC as I did before that, but unfortunately, my first PCIe slot is still running at 1x speed.

Here's what I tried :
- Clear CMOS
- Cleaning the whole system and reseatting the GPU
- Fiddling around in the BIOS
- Updating the BIOS to the latest version, was running 0507 and updated to 0512.
- Loading default values and reconfiguring it as it was.

I hope someone can help me with that, that could save me a lot of headache and waste of time

ChatDaw · May 4, 2016

Up.

dragoon20005 · May 4, 2016

based on the issues

it looks like the mobo itself has broken tracks to the PCI-E slots so that is why your PCI-E lanes is cut that bad

you will need to find a new LGA775 board

ChatDaw · May 4, 2016

6 hours ago, dragoon20005 said:

based on the issues

it looks like the mobo itself has broken tracks to the PCI-E slots so that is why your PCI-E lanes is cut that bad

you will need to find a new LGA775 board

Hey, thanks for the answer.

I actually managed to fix the issue. I'm back to x16 on my 9500GS now.
All I needed to do was take out the card, boot up without any GPU/PCI device plugged in and shut down the system then put the GPU back in.
Wasn't that hard in the end but... an irritating issue