Second PCIE slot issue

Dohnny Jepp

Being the exceptionally clever and competent person that I am I bought a new CPU and an SSD to put into my computer. For around 80 euro and 10 hours of effort I've managed to make my computer significantly worse

I have a P8z68 v lx mobo, and I run 2 radeon 6870's in crossfire.... or else I used to run two in crossfire. Since I took apart and put back together my computer I can't get my second gfx card recognised. Both cards work because I've tried them both as the primary card. I've uninstalled all AMD drivers and used a driver sweeper twice. Firstly installing them one at a time, and secondly both at the same time. It didn't make a difference though, the device manager and CCC still don't recognise the second card.

I think there are 2 possibilities,

1. There is an option in the bios I need to change. I did reformat after I upgraded but I thought bios were unaffected by reformats.

2. I damaged the slot at some point in the upgrade....

Maybe someone has had similar experience and can point me in the right direction.

ED E

Are they both powered by the mobo itself or are there extra PCIE power pins in em? My suspicion is that you've increased draw from the boards power and thus there's insufficient power for both now.

Dohnny Jepp

ED E wrote: »

Are they both powered by the mobo itself or are there extra PCIE power pins in em? My suspicion is that you've increased draw from the boards power and thus there's insufficient power for both now.

2 6 pins in each of them. I also have a 700w psu.

Never had an issue with them before until now.

Even with them both having 2 6 pin connecters from psu, do you think it could still be that issue?

Dohnny Jepp

Would clearing the CMOS help do you think?

ED E

Never done CF/SLI so I'm not sure. Somebody else on here may know. A cmos reset cant hurt but I doubt that'd do it.

If you wanted to test you could swap the CPU back but that would consume some TIM and time.

justjustin

Dohnny Jepp wrote: »

...I bought a new CPU...

...2 radeon 6870's in crossfire....

I think there are 2 possibilities,

1. There is an option in the bios I need to change. I did reformat after I upgraded but I thought bios were unaffected by reformats.

2. I damaged the slot at some point in the upgrade....

... I also have a 700w psu...
.

More info needed here:

What was the cpu upgrade to and from?

BIOS should be unaffected by a reformat and it is possible that you damaged 'a' PCI-e slot during the upgrade - unlikely, but possible.

What PSU do you have? Brand and model. Depending on the PSU it might not just be able to handle the extra wattage an upgraded CPU 'may' demand.

Have you tried just installing one card in the secondary slot and seeing if that works? You could maybe isolate a slot as the problem that way.

Dohnny Jepp

My mistake, I meant cpu fan. The cpu is unchanged. I just wanted a better Heat sink.
Neither card works in the second slot. The screen just stays black.
The psu is a 700 w ocz modxstream pro. Or so it says on the psu anyway.

My cpu is a i5 2500k sandy bridge

justjustin

Is there an option in the BIOS to set the default GPU type? I have a similar Asus board (AMD) but I do not have any integrated graphics, nor does my board support it, but I see that yours has "LucidLogix® Virtu - Universal Switchable Graphics Technology". Is it possibly something to do with this not playing nicely with a fresh install?

Have a look through the BIOS and see what you can find relating to either GPU/iGPU and PCI-e. There is usually some default option, which could be either Auto, iGPU, PCI-e or Hybrid or something along those lines. If that is set to auto, it could be worth trying it on the PCI-e setting.

For what it's worth, I use Display Driver Uninstaller from guru3D if I ever need to remove video drivers. That could also be worth a shot, just make sure to reboot into safe mode when it prompts you.

These are just some things you could try try but unfortunately it does sound a lot like your second PCI-e slot could be dead. I had trouble with my 7850s when I first crossfired them on an existing Windows 7 install - since then I have installed Windows 8.1 twice and had absolutely no issues with crossfire.

Dohnny Jepp

justjustin wrote: »

Is there an option in the BIOS to set the default GPU type? I have a similar Asus board (AMD) but I do not have any integrated graphics, nor does my board support it, but I see that yours has "LucidLogix® Virtu - Universal Switchable Graphics Technology". Is it possibly something to do with this not playing nicely with a fresh install?

Have a look through the BIOS and see what you can find relating to either GPU/iGPU and PCI-e. There is usually some default option, which could be either Auto, iGPU, PCI-e or Hybrid or something along those lines. If that is set to auto, it could be worth trying it on the PCI-e setting.

For what it's worth, I use Display Driver Uninstaller from guru3D if I ever need to remove video drivers. That could also be worth a shot, just make sure to reboot into safe mode when it prompts you.

These are just some things you could try try but unfortunately it does sound a lot like your second PCI-e slot could be dead. I had trouble with my 7850s when I first crossfired them on an existing Windows 7 install - since then I have installed Windows 8.1 twice and had absolutely no issues with crossfire.

Yeah I have the option I think you are referring to set to PCIe/PCI.

Yeah I've tried driver sweepers and reinstalling numerous times. I suppose A reformat might not be a bad idea just to make sure it wasn't a dodgy format. It's a real shot in the dark though.

justjustin

Dohnny Jepp wrote: »

It's a real shot in the dark though.

True, but maybe worth a shot if you have the time. Another thing, have you installed all Asus drivers for the board when you reinstalled windows?
And did you install the same version of windows, or did you for example move from Windows 7 to Windows 8/8.1/10?

Another thing to try would be a linux live distro from USB. Boot that up and you could check to see if it detects the second GPU.

I do feel, however, that somehow your secondary PCI-e slot is busted. Possibly some static discharge while changing the CPU HSF. The best way to avoid this type of damage is to leave the PC plugged in to the wall, but turn off the PSU switch or the socket switch on the wall/socket board. While doing any work always try to keep one hand on the PC case and you will be grounded.

The fact that you only get a black screen with a single GPU in the secondary slot is quite damning I'm afraid, but don't give up on it just yet

Edit: Just to exhaust every avenue, have you tried a different set of AMD drivers or are you just trying the same ones over and over?