Blur Busters Forums

Question:
Is raising the pixel clock value in CRU beyond the maximum pixel clock of a monitor harmful? Could it damage the monitor?


At present, I use a Dell P2720D (great monitor, by the way).

CRU tells me about this monitor:
V rate: 49-75 Hz
H rate: 29-113 Hz
Max pixel clock: 280 MHz

By default, this monitor comes with 2560x1440@60Hz.

I created a custom resolution of 2560x1440@74Hz (the difference between 60 Hz and 74 Hz is worth it in games!).

But I could only achieve this refresh rate of 74 Hz by using settings that imply a pixel clock of 291.29 MHz - which is beyond the specified max pixel clock of 280 MHz. - (The H rate is within the permitted range (see above): 110.337 kHz.)


Without getting too technical, does disrespecting the maximum limit of the pixel clock reduce the life-span of a monitor or cause any damage?

All I can say is, that the monitor picture is normal, responsiveness in games is excellent - but I am worried because I did not respect the maximum pixel clock. (I am not that worried when creating lower custom resolutions, of course)

Thanks for useful replies.

Though there are no answers so far, I would like to add something more to my question:

If I have a monitor with a native resolution (and a custom refresh rate) of "2560x1440@74Hz" and set it to "1920x1080@74Hz" but using "no scaling" (in my case: no GPU scaling as "display: no scaling" is unavailable", I don't know for what reason...), what pixel clock is in effect then? The lower pixel clock of 1920x1080 or still(!) the higher pixel clock of the higher (native) resolution?

I just found in some thread of this forum that "display (down)scaling" uses the "real, lower resolution", whilst "GPU scaling" just uses the normal resolution and emulates a lower resolution, is that right? - I suppose, using the "no scaling" option (via GPU) still means: the higher resolution is active and also its higher pixel clock, right?


I guess, someone must be able to answer these questions.
Many thanks in advance.

Anyone able or willing to help with these questions?

Topic hasn't had a response in a few months, but if you exceed the capabilities of an LCD panel, you get an unaligned shaky picture that randomly misses pixels on various scanlines, until you go back to a mode that it supports. May need to boot in Safe Mode to get back to a supported mode, so you can change the parameters back to something that works.

sempronius wrote: ↑

05 Apr 2020, 18:15

Anyone able or willing to help with these questions?

Unlike CRTs, it's relatively safe to drive LCD monitors past their native specs. No guarantees, but it's very rare that a monitor gets damaged.