VEGA 56 Freesync stuck at 60fps cap - but only at 1440P

[555BUK]

I have a bit of an odd problem and not sure whether to post this within Graphics or Monitor section.

My new VEGA 56 and DELL S2719DGF monitor refuse to run above 60fps at 1440P. All other resolutions below 1440P run 144Hz/FPS fine, but I seem to be "bandwidth capped" at 1440P. AMD Control Panel shows Current Link Settings for Display Port are running at 2.7 Gbps x 4 (10.8 Gbps). This is not enough bandwidth for 1440P @ 144Hz so is clearly the issue, but I cannot work out whether it is my monitor or graphics card which is not playing ball. Latest 19.2.3 drivers installed and the monitor is DP 1.2 spec so should support 17.28 Gbps.

I have reinstallled various drivers, moved DP between outputs but always same result. Freesync works perfectly at any resolution below 1440P so not a VSYNC issue.

Any ideas before I send the monitor back under DSR?

 

[Davedree]

Right click on the desktop and go to display settings, Advanced display settings, Display adapter properties for display 1,
Monitor tab,

Is the screen refresh rate set to the panel resolution, ?

 

[tamzzy]

2.7gbps x4 is dp 1.1 mode. need to change it to dp 1.2 to run 1440p 144hz

 

[555BUK]

Right click on the desktop and go to display settings, Advanced display settings, Display adapter properties for display 1,
Monitor tab,

Is the screen refresh rate set to the panel resolution, ?

You Sir, are a genius - or I am a fool. I spent hours trying to resolve this. Forcing the Display Properties to 144Hz @ 1440P has dooubled the bandwidth.




Now, my monitor actually supports 155Hz OC, which of course is working at every resoltion except 1440P. But foir the timebeing i AM HAPPY @ 1440P 144Hz.

 

[Davedree]

Enjoy

 

[555BUK]

Is this a quirk of AMD drivers? Every other resolution runs freesync 144/155Hz fine out fo the box, so it seems strange that my monitors native resolution required special tweaking. 1440P is very common nowadays afterall.

 

[tamzzy]

no, happened with my nvidia card too. had to set the refresh rate manually the very first time i plugged the monitor in.
once it's set though, it stays set. so no biggie

 

[tamzzy]

Now, my monitor actually supports 155Hz OC, which of course is working at every resoltion except 1440P. But foir the timebeing i AM HAPPY @ 1440P 144Hz.

silly question, but you've set overclocking enabled on the monitor itself? (had to be asked)

 

[555BUK]

silly question, but you've set overclocking enabled on the monitor itself? (had to be asked)

Yes, I set it on the monitor. When I force 1440P @ 144Hz within Windows Display Properties and set OC (155Hz) within monitor settings, my PC drops the refresh rate down to 60Hz. All other resolutions support 155Hz automatically except 1440P. Perhaps it's a Windows 10 thing rather than AMD, but as I cannot actually see the difference between 144Hz & 155Hz it is no biggy.