Question Why does my GPU not work in a PCIe x16 (at x4) slot?

[Arturas Kulickis]

Hi all,

I recently started dabbling with old PC hardware as I find it all quite interesting.
For the purposes of testing old AGP and PCI cards, I thought I’d get a test bench together with an older motherboard.
I then discovered ASRock made weird motherboards that had AGP, PCI, and PCIe slots. I thought “sweet, I can make an all-in-one test bench for all hardware”. In hindsight this was a very stupid thought, but oh well.
I purchased a ASRock 4CoreDual-VSTA (which was a pain to find for sale, let me tell ya) and felt confident going in.
I put in a Core 2 Extreme QX6700, 2GB of DDR2 and a Radeon 9600Pro AGP card. Worked great, got Windows 7 running with no issues.
Problems arose however when I tried to plop in a NVidia NVS 510 to test the PCIe slot. The PC would spin to life as usual, but there was no video output. Additionally, there were no beeps from the debug speaker I plugged in.
After some googling I found the motherboard didn’t have true PCIe x16 capabilities, but essentially has a PCIe x4 slot posing as x16.
After more googling I found some sources saying that x16 GPUs should be able to function in x4 slots, although at reduced performance.

Did I do a big dumb dumb or is there something that might actually be wrong?

 

[Lutfij]

Did you make sure you were on the latest BIOS version for your motherboard?

Problems arose however when I tried to plop in a NVidia NVS 510 to test the PCIe slot. The PC would spin to life as usual, but there was no video output.
Did you try clearing the CMOS? Disconnect from the wall and display, then remove the CMOS battery from the board, then press and hold down the power button for 30secs. Replace the battery after 30mins.

 

[Eximo]

Hmm, Geforce 510 was an OEM only card. May not play nice with off the shelf hardware to start.

The other factor may be power. A 4x connection might be fine, but to power the card might need more than what the 4x slot can provide. You also likely have PCIe 1.0 and even the 510 was a PCIe 2.0 card.

 

[Arturas Kulickis]

Did you make sure you were on the latest BIOS version for your motherboard?

Problems arose however when I tried to plop in a NVidia NVS 510 to test the PCIe slot. The PC would spin to life as usual, but there was no video output.
Did you try clearing the CMOS? Disconnect from the wall and display, then remove the CMOS battery from the board, then press and hold down the power button for 30secs. Replace the battery after 30mins.

The BIOS is fully updated to the latest version from ASRock.
I have tried the trusty CMOS reset before, but that didn’t work sadly.
Thanks for the reply!

 

[thestryker]

If you're sure the video card works then it's either the PCIe slot or not enough power to the slot. If you have any other PCIe cards available (NIC/sound etc) that would be good for checking the slot itself.

I did some reading on the chipset and it looks like you should be able to boot with AGP and PCIe video cards in at the same time so perhaps that could help troubleshooting.

 

[steven_edwards]

I'd also suggest simplifying things and pulling out the AGP card and only testing the PCIe card first in the various PCIe slots. If it works with the AGP card removed then you know there is a compatibility issue or hardware limitation.

 

[Eximo]

I'd also suggest simplifying things and pulling out the AGP card and only testing the PCIe card first in the various PCIe slots. If it works with the AGP card removed then you know there is a compatibility issue or hardware limitation.

There is only one PCIe slot on that board.

This was early days, and they quickly launched PCIe 1.1 to cover defects, one of which was power delivery. Also why USB 1.0 systems were to be avoided at that time. Plug in a fancy light up mouse and it would take down the motherboard from over current.

 

[BFG-9000]

I'll suggest that you read through this support thread for that board. It's a VIA chipset so some weirdness is to be expected, but some BIOS revisions should indeed run PCIe 2.0 cards like your Kepler one.

 

[BFG-9000]

Here's the unofficial beta BIOS that enabled support for PCIe 2.0 cards.

As an extra bonus it also allows 4GB of RAM to be installed, but read that thread, as this didn't prove to be stable for everyone.