CRU / Dell P2720D / pixel clock / add monitor data

[ToastyX]

(03-24-2020 11:40 PM)sempronius Wrote:  Hm, I am not sure I understand.

I have *two* options for "no scaling", one for "display scaling" and one for "GPU scaling".

With the Dell P2720D, the "no scaling option" when set at "display scaling" does nothing, but it works when set at "GPU scaling".

With the HP 27xq, the "no scaling option" works in either case.

So, as I see it, there must be a difference between the "no scaling" between "GPU scaling" and "display scaling", or not?

Display scaling sends any resolutions listed in CRU to the monitor. The graphics driver automatically adds some common lower resolutions as scaled resolutions. That's what the "no scaling" option affects with display scaling. If you use GPU scaling, then it will affect all non-native resolutions.

[sempronius]

I still do not understand, sorry, why one monitor (HP 27xq) can do "no scaling" when using "display scaling" (centered image with black bars), whereas the other monitor (Dell P2720D) can only achieve "no scaling" when using "GPU scaling" - NOT when using "display scaling". I mean, the lower resolutions (in case of the Dell) had also been added by the graphics driver because they were there even before I started using CRU.

Is this simply a limitation of the capabilities of this monitor as opposed to the HP?

Please, excuse me being stubborn, or perhaps, I am just confused, tired...

[ToastyX]

I don't know how else to explain it.

If you have a 2560x1440 @ 60 Hz monitor, and the EDID defines 1920x1080 @ 60 Hz, then "no scaling" will do nothing at 1920x1080 @ 60 Hz with display scaling because the monitor is handling the scaling.

If the EDID does not define 1920x1080 @ 60 Hz, the graphics driver automatically adds 1920x1080 @ 60 Hz as a scaled resolution, so "no scaling" will work in that case.

[sempronius]

(03-25-2020 11:12 AM)ToastyX Wrote:  If you have a 2560x1440 @ 60 Hz monitor, and the EDID defines 1920x1080 @ 60 Hz, then "no scaling" will do nothing at 1920x1080 @ 60 Hz with display scaling because the monitor is handling the scaling.

Since "display scaling: no scaling" does not work with the Dell monitor, this would mean that 1920x1080@60Hz is defined by the EDID, as I understand it now... Hope, this is correct.

Quote:If the EDID does not define 1920x1080 @ 60 Hz, the graphics driver automatically adds 1920x1080 @ 60 Hz as a scaled resolution, so "no scaling" will work in that case.

Since "display scaling: no scaling" (and also "GPU scaling: no scaling") works with the HP monitor (centered image with black bars), I conclude that 1920x1080@60Hz is NOT defined by the EDID but added by the graphics driver.


Additionally:
- Using GPU scaling, the pixel clock of the higher (=the native) resolution is still in effect, whilst with display scaling the corresponding pixel clock of the lower resolution is in effect.

- With GPU scaling (if what I wrote about the pixel clock above is true), the stress on the monitor electronics and graphics adapter is still the same as with the native resolution, right? So trying a lower resolution with black bars will not help to keep the GPU temperature lower and the monitor more within its specifications? I guess, this is correct...


Hope, I got all these things right now. :-) Thanks.

Is there a drawback to GPU scaling as opposed to display scaling? Some sites talk of higher input lag and such things but others say that this is nonsense.

I sometimes (for gaming purposes) run the Dell overclocked (from 60Hz to 74Hz), but not for the desktop (reading, working, browsing the web...).
Dell states that overclocking a monitor voids its warranty. Do you think (or know) that this is even detectable?

[ToastyX]

You're overcomplicating this. If the resolution is listed in CRU, then "no scaling" has no effect unless GPU scaling is enabled. If it's not listed in CRU, then it's a GPU-scaled resolution.

GPU scaling scales lower resolutions to the native resolution. Display scaling sends the resolution to the monitor. Keep in mind that the monitor will scale lower resolutions to the panel's native resolution, so a lower resolution at a higher refresh rate might not be less stress than the native resolution at the same refresh rate.

(03-25-2020 01:44 PM)sempronius Wrote:  Is there a drawback to GPU scaling as opposed to display scaling? Some sites talk of higher input lag and such things but others say that this is nonsense.

I don't know where people are getting that there's higher lag with GPU scaling. People only say this with NVIDIA, but it has never been proven.

(03-25-2020 01:44 PM)sempronius Wrote:  I sometimes (for gaming purposes) run the Dell overclocked (from 60Hz to 74Hz), but not for the desktop (reading, working, browsing the web...).
Dell states that overclocking a monitor voids its warranty. Do you think (or know) that this is even detectable?

No, they won't know.

[sempronius]

Alright, many thanks for all your time and answers. :-)