AMD screen tearing multiple monitors using multiple ports

[davidhawke]

Hi,

Awesome software.

I have a MSI rx580 8GB card and 2 x LG 27mp68vq freesync (1920 x 1080p) and 1 x LG 34um59 freesync (2560 x 1080p) monitors that i am using as a 3 monitor set for sim racing , i have since found out the hard way that i can't get the monitors to sync their refresh rates as i can get either the 34um59 fine and the 2 x 27mp68vq with tearing or both the 27mp68vq fine and the 34um59 with tearing.

The 34 has only hdmi x 2 as input and the 27's have 1 x hdmi , 1 x dvi and 1 x vga (i know i should have researched this more and bought monitors with dp inputs)
The card has 2 x hdmi and 2 x displayport and 1 x dvi (i have tried all combinations except dvi with the same result). I have both passive and active dp to hdmi adapters. I am using the hdmi inputs on all 3 monitors.

I believe it's because whichever i define in eyefinity as the preferred monitor sets the timing for all 3 , but there are slight timing differences between the hdmi and dp .

eg
34um59 refresh rate is 74.991hz and because it's the preferred monitor it outputs that frequency across both hdmi and dp but the 27mp68vq is 74.975hz(from memory) via hdmi .
My theory is i should be able to create a custom resolution with 74.991hz for both the 27mp68vq via hdmi to make them sync with the 74.991hz refresh rate being output to all 3.

Will this work as i expect ? or other suggestions for a fix would be appreciated.

Thanks

David

[ToastyX]

The only way to make sure all monitors can be synchronized is to make the horizontal/vertical totals and the refresh rate exactly the same, but there's still no guarantee that the video card will be synchronized across the different ports.