Overclocking Dell U2415 Fail

[t4rj4n]

Hello,

I failed to overlock the Dell U2415. I am creating custom resolutions using the NVidia Control Panel Settings and can see frame skips starting with 62 HZ. For testing im running https://www.testufo.com/frameskipping either with camera or with bare eyes.
The monitor is connected via DisplayPort but HDMI gives the same results. The OSD is even showing higher refresh rates then 60hz.

What Im wondering is, why even the official supported resolution 1280x1024@75hz does frame skipping.

Does anybody have any ideas? I know that this is no gaming monitor, but i would be happy to do 66 HZ or higher in a lower resolution.

I switched from my Dell 2209WA doing 1680x1050@75hz for a larger resolution.

Greetings from Tarjan

[t4rj4n]

To add some more information:

I am using Windows 10, i could test Windows 7 as well with identical behavior
I tried CRU, which does not seems to work: custom refresh rate does not appear in monitor settings, after loading successfully unsigned custom inf.
I typically use the "CVT reduced blank" timing, but this timing and the others as well wont let me go higher then 61HZ without frame skipping.
I installed this nvidia pixel clock patcher without change.

The monitor advertises as:
HF: 30 kHz - 83 kHz -> this would max vertical fr. to 69HZ at max resolution and does not explain why i cant do 1024x768@75hz
VF: 56 Hz - 76 Hz

I think i have to accept the fact, that the monitor, while accepting up to 1920x1200@84HZ, skips anything over 61HZ internally. Poor implementation though.

[t4rj4n]

I managed to use CRU for overclocking. I wasn't aware, that the overrides can be set directly to the graphics driver without inf plus i had to add a CEA-861 block.

Nevertheless, exact the same picture...

61Hz: works, 62Hz and above: frame skipping.

Overclocking capability: 1.6 %

Maybe i should look for a different monitor. I just want to squeeze the last bit out of this one.

Greetings