HD7950: PCIE at 1x 2.0, instead of 16x 2.0, reboot fixes it!

[Firestarter]

Hey guys, I'm having a bit of a problem here with my new build. I have an Asrock Z68 Pro3 Gen3, a Powercolor (or was it Sapphire? I forgot) HD7950 and a Intel 2500K. Both the GPU and CPU are overclocked somewhat, and I've had to raise the minimum GPRAM clock speed to fix issues with the desktop at 120hz. I've installed the latest 79xx compatible Catalyst drivers, and used the Intel utilities for the chipset. As far as I know, the drivers are installed correctly.

My problem is that after a while (several hours), the PCI Express link seems to get stuck in its power-saving mode. Normally, GPU-Z reports that the PCI Express link is at x1 v1.1 when idle, and it correctly ramps up to x16 v2.0 when playing a game or running the GPU-Z render test. Performance in-game is as expected (and pretty awesome) and all is good. After a few games of BF3 though, it seems to not want to ramp up to more than x1 v2.0. So instead of running at x16, the PCI Express link stays at x1 (even though it goes from v1.1 to v2.0). Needless to say, this slows down BF3 tremendously, and even makes my desktop very sluggish when I run the GPU-Z render test or indeed anything graphically related. If I reboot, the problem is fixed and performance is as it should.

I've tried disabling the PCI Express link power management in the Windows Power Management console (seems to have no effect at all), and I've looked around in the EUFI for power management related settings and found none. I haven't found any settings in the CCC related to PCI Express power management.

Here's a screenshot of GPU-Z, showing the faulty link state:




Does anyone know of similar problems, whether it's a bug in the drivers, some silly EUFI setting or something like that? Has anyone experienced something similar? My google-fu is not turning up anything

[riviera74]

Check the UEFI first to see if it is set correctly. If not, alter it to match PCIe 16x. That is most likely your issue. If that fails, you need a UEFI update.

Oh BTW, end the overclocks first.

[vargis14]

Cannot help you with your problem but I am very Jealous or your 120hrtz monitor.Could i know what Model and size it is and what do you think of it?
Income tax check is coming and i am looking at the Asus 27" 3d vision 2 120hrtz monitor,But it is priced around 650$.

But back in 2004 or 2005 i did buy that $1000 24 inch 1920x1200 dell "2405 i think" monitor as soon as it came out,cannot remember if it was a IPS or a Tn panel.It had a great picture but it had noticable ghosting in certain situations.

[Firestarter]

For anyone who found this bustling forum of breathtaking activity: The problem may have solved itself with the 12.3 WHQL drivers, as the PCI express interface seems to throttle down to x16 v1.1 now, instead of x1 v1.1.

[Firestarter]

Bumping this because it isn't resolved. I'm not 100% sure if standby causes it, or zero-power. Either way, the graphics card and/or the motherboard limit the PCI express interface to 1x after that

[TDIdriver]

Open GPU-Z, click the "?" next to where it lists the PCIE details. Or is that how you got the render test?

[Firestarter]

Open GPU-Z, click the "?" next to where it lists the PCIE details. Or is that how you got the render test?

Yeah that is how you get to the render test, that's how I knew that something was up.

[UberGerbil]

Have you verified this problem persists when everything is clocked at stock (ie reset the BIOS to defaults and turn the GPU back down also)?

[stickfinger]

I've got the same issue as you, but my Sapphire 7950 OC is even worse, giving absolutely crap performance in modern games and randomly jumping from PCIE 1x 1.1 to PCIE x1 2.0
At first the card was running just fine at x16 2.0, but after a couple of weeks performance suddenly dropped tremendously.
So i bought a MSI Z77a-GD65 motherboard, due to problems with the one i had (p67-gd65), but apparently that did not solve the problem.
Tried reseating the card, different drivers and i even cleaned the gold PCIE connectors carefully but nothing seems to help.

On a positive note, i'm glad i'm not the only one with this problem

[ClickClick5]

*cough cough*
viewtopic.php?f=3&t=81356

Check USB3.

[stickfinger]

USB 3.0 has nothing to do with it if your bios doesn't have that "R_USB30 Turbo' setting.
Disabling USB 3.0 doesn't help either