I mean how can i know it's working fine ? and 75 hz is safe ? or i should go for 70 ?like any overclock. it might work. it might brick the monitor.
I mean how can i know it's working fine ? and 75 hz is safe ? or i should go for 70 ?
You can't run a display with larger refresh rate than specified. It does not work like that. In best case you will get blurry picture... or a part of original picture. But most likely it will end with black screen until you will return back to specified refresh rate.
I heard that i can overclock it through nvidia control panel ( making custom res )
Only if your display does support these custom modes. Check manual about that. However it is not possible to have 75 Hz refresh rate on panel rated for 60 Hz. Even if you manage to get display circuit work faster (I'm curious, how), panel refresh speed is hard stop here.
I see what you did. And even better results are possible with CRU utility. Where it is possible, obviously.
Unfortunately you see what you wish to see. Signal processor in monitor will not work faster - it simply is not supposed to pass through more data than expected by manufacturer. In reality there are 3 possible outcomes:
- Fallback to same 1920x1080@60 Hz resolution/refresh rate specified as upper limit for monitor. It does not matter what you see in configuration dialog at same time.
- Switching to resolution where asked refresh rate works. Like falling down to 1280x1024@75Hz with grainy stretched image on screen. Or switching to 1920x1080@30 Hz. Depends from how particular monitor can process that.
- No picture at all with blank screen and optional "No signal" message.