Acer RT280K overclock

[porina]

With the news today that nvidia will be introducing a level of support for FreeSync, I thought I'd get to know my only FreeSync monitor better by overclocking it!

On the manufacturer's webpage, it lists the vertical refresh rate as 23 - 80 Hz. Normal display settings stop at 60 Hz, so can I get a bit more? I don't recall trying to OC a display before. System has a GTX 970 in it with current driver. Went into custom resolutions and had a play.

With timings set to automatic, I started at 3840x2160. Went up to 70 Hz no problem. 72 Hz fine. 75 Hz, nope, blank screen. 73 Hz, nope. Ok, some limit there.

Next was 2560x1440. Found same again, 72 Hz ok, 73 Hz blank screen. Is this a hard limit?

Ok, one last try at 1920x1080. 72 Hz ok. 75 Hz ok. 80 Hz gave "input not supported" message on display, as opposed to blank screen before. Back off to 79 Hz, ok.

I wonder if this is then some bandwidth limitation, but if so, why same limit for both 1440p and 2160p? There are options in the menu for other timing methods which I haven't tried yet, and I wouldn't know where to start with manual timings.