Monitor Tests Forum

My old LG monitor works fine overclocked at 75Hz, but after waking from sleep or hibernate, it resets to 60Hz.
Even if I delete the 60Hz profile to force 75Hz, it doesn't actually work at 75Hz as the setting says, but it's skipping frames and actually working at 60Hz.

So the only solution so far is to restart the PC, which is tedious.

Does anyone know any other solution, that would force the actual overclocked refresh rate after waking from sleep/hibernate?

(Using Windows 7 and a Radeon 4670. Overclocked with CRU.)

Is the refresh rate listed in the Windows screen resolution settings? Are you saying Windows shows it's set to 75 Hz but it's actually running at 60 Hz? That would be an AMD driver bug. Does changing the refresh rate to 60 Hz and back to 75 Hz work around the problem?

(02-08-2014 02:41 AM)ToastyX Wrote: [ -> ]Are you saying Windows shows it's set to 75 Hz but it's actually running at 60 Hz?

It's actually only showing it at 75Hz until I close and re-open that advanced monitor setting window. Then it shows the refresh rate at 60Hz and the frame skipping test also shows it's running at 60Hz.

Normally (without sleep/hibernate), when I change the refresh rate I'd get 1 or 2 seconds black screen and then get the confirmation window with a 15sec count down.
But if I do this after sleep/hibernate there is usually no black screen, the Hz "change" is instantaneous.

Except sometimes for the very first time when I switch from the 75Hz setting (=a properly working 60Hz) to the 60Hz setting. In that case the black screen happens for a second and then the screen ends up being very choppy and that frame skipping test looks like this:




I'll try with an older AMD driver. If you have any other ideas let me know.
Also the frame skipping test is not always consistent between Firefox and Chrome, at least not when the problems happen. When everything is working fine, it usually is.

Update:
I tried with an older AMD driver (from 2010) and it was the same.

Then I removed the AMD driver and started using the stock Microsoft driver (WDDM 1.1) and so far it works fine. No problems with resetting back to 60Hz after sleep or hibernate.
The only downside is that hardware acceleration in Firefox doesn't work with this driver, but then even with the AMD driver it didn't work well (occasional blurry text... known issue).

If you want to use AMD's driver, check if restarting the driver works around the problem: https://www.monitortests.com/restart.zip

You'll have to run it every time after waking up from sleep, but at least you won't have to reboot.

Thanks a lot! Restarting the driver does indeed get back the previous refresh rate.

Though if hardware acceleration is enabled in Firefox when doing that, Firefox will crash. I don't intend to use hw accel in FF on this PC, so I should be fine. But it could be a problem if it crashes some other program... I'll see how it goes.


BTW, I tried with a newer MS driver (2011, from Windows Update) and it has the same issue. Only the older MS driver (2009, included in W7 out of the box) works fine in this regard.
Also, I overclocked another monitor with a Radeon 7850 and haven't noticed any problems with resetting back to 60Hz after hibernate. So it might be limited to the 4000 series and/or the legacy drivers.