Asus PG279Q won't display 1440p

[sawf]

Hi,

I have had a bit of a search but can't find anything that relates to this issue so sorry if this has been discussed. I have recently changed monitor from a Asus MX27AQ to a Asus ROG PG279Q. On the MX I set my MISTer up to run 1440p using this guide: https://www.retrorgb.com/mister-1440p-1 ... aling.html - which worked great. The PG however just gives me a "no signal" on everything except the default 720p 60hz, even 1080p 60hz doesn't work. Upon checking the manuals for the supported resolutions the PG supports barely anything in comparison to the MX but the weird thing is even the supported resolutions don't work on MISTer like 1080p 60hz.

Does anyone have any experience with MISTer on the PG? Are there any other settings or timings I can try to get it to work?

Thanks

[FoxbatStargazer]

There's a built-in 1440p now with video_mode=12, I would just try that.

Although it's concerning that 1080p (video_mode=8) doesn't work.

[sawf]

Yeah I tried that too but it gave the same result, I was thinking 1440x1080 was just outside of it's range until I tried 1080p and that didn't work. It just seems really odd that nothing will display apart from 720p.

[morf77]

You will most likely need a custom video mode. More than likely you have issues using the default video modes because it's a G-Sync monitor. I found a modeline for 1440p on this website https://www.ixbt.com/monitor/asus/pg279 ... p-over.txt

Modeline............... "2560x1440" 241,500 2560 2608 2640 2720 1440 1443 1448 1481 +hsync -vsync

This translates to video_mode=2560,48,32,80,1440,3,5,33,241500 in the mister.ini

That pixel clock of 241,500 is way above the supported limit of the mister however. Even if it does produce an image it's very doubtful this won't cause any problems while running a game etc. I haven't been able to find a modeline for that monitor for 1920x1440 resolution. This would reduce the required pixel clock a lot.

For 1080p I haven't been able to find a custom modeline either. Though I did find a text file on https://www.ixbt.com/monitor/asus/pg279 ... o-hdmi.txt which claims 1080p on that monitor supports these standards:

CE video identifiers (VICs) - timing/formats supported
1920 x 1080p at 60Hz - HDTV (16:9, 1:1) [Native]
1920 x 1080p at 50Hz - HDTV (16:9, 1:1)
1280 x 720p at 60Hz - HDTV (16:9, 1:1)
1280 x 720p at 50Hz - HDTV (16:9, 1:1)
720 x 480p at 60Hz - EDTV (16:9, 32:27)
720 x 576p at 50Hz - EDTV (16:9, 64:45)
640 x 480p at 60Hz - Default (4:3, 1:1)
NB: NTSC refresh rate = (Hz*1000)/1001

Using https://www.mythtv.org/wiki/Modeline_Database there are 3 HDTV 1080p modelines listed at 60hz. I've converted them for you - using the web app in my signature - you could try them out and see which one - if any - works:

video_mode=1920,88,44,148,1080,4,5,36,148350
video_mode=1920,88,44,148,1080,4,4,37,148500
video_mode=1920,88,44,148,1080,4,10,30,74180

You could apply a similar workflow to find a working 1920x1440 video_mode - google for existing modelines using that resolution and convert them to video_mode using the web app. Try to pick modelines with a low pixel clock as this will increase the odds it can be handled by the mister and not only your monitor.

PS: the online txt files linked in this post are outputs of an app called Monitor Asset Manager https://www.entechtaiwan.com/util/moninfo.shtm You could try running this on windows and see if it can help you give more information on supported modelines for your monitor.