I have 4 identical LG 1440p monitors all connected to a RX 580 which has 3 DP and one HDMI port. All identical 4 monitors can support 144hz, 120hz and 60hz. I have them setup on a SIM RIG where the 4th monitor (data only monitor) is connected to the HDMI port and the three "gaming" monitors are using eyefinity to show up as 7680 x 1440p. My left monitor of these three combined monitors will not show a picture unless I bring all 3 of them down to 60hz using Display Settings in Windows. When the setting is set to 144hz or 120hz, only this left most monitor goes dark while the other two still remain lit and show the refresh rate at 144hz.
What can I do to get all of the monitors (at least my gaming 3) to run at 144hz. I'm running latest AMD 2020 software at 20.11.1 released 11/4/20.
Need to post your Computer specs especially the Make & Model of your GPU card.
Depending on which GPU Card you are using determines what Resolutions and frequencies you can have for multiple Monitors connected.
Generally the more monitors you have connected the more Bandwidth it requires so the lower the Resolution and Hz is needed to run all the monitors depending on the GPU card you are using.
Some GPU card can run Higher Resolutions and HZ for 3 or more monitors while other can not.
Thanks for asking. You make a good point. I'm interested if my GPU falls in that category.
HomeMade box with: Intel i5 3570, 16 GB Ram, 256GB SSD, 2 TB HD, Radeon RX 580 Black Edition 8GB with 3 DP, 1 HDMI, 1 DVI outputs running Windows 10 64 bit.
I'm running 4 of the exact same Monitor. They are LG 32GK650F 1440p. I have 3 connected via DP and 1 via HDMI.
My issue is that the #1 monitor connected via DP only shows picture at 60hz, while the other 2 DP's will show picture at 144 hz. The HDMI is at 100hz.
Also I can add that that I'm running eyefinity on the 3 DP monitors to make them as one 7680 x 1440p. So they are all forced to run at same refresh rates. The monitors do support FreeSync. So when I set the monitors to 144hz only Monitors #2 and #3 come on. When I change it to 120hz the issue persists. Not until I change the single extended 7680 x 1440 display of 3 monitors to 60hz do #1, #2, and #3 monitors all show the desktop.
Found this Wiki article concerning AMD Eyefinity GPU cards: https://en.wikipedia.org/wiki/AMD_Eyefinity
The higher the Monitors resolutions the lower the Frequencies that are needed to run Multi-Monitor setups depending again on your GPU Card.
Can you Daisy-Chain your LG monitors to each other and then connect it to one of your GPU's DP Outputs?
Maybe use a MST to connect all three DP Monitors to one GPU DP Output.
Does all three LG monitors connected to the DP Port, Will they run correctly if the Hz is the same for all three? I would start at 60Hz and then increase all three monitors at the same time to see if it is a limitation of the GPU card.
It is possible your DP ports can't run 3 monitors above 60 hz depending on the Resolution you have set.
Your RX580 can support up 6 Monitors depending on the Resolution and Hz.
I suggest you open a AMD Service Request (Official AMD Support) and ask them from here: https://www.amd.com/en/support/contact-email-form
NOTE: FYI- Found this Intel Support that shows the Maximum Resolutions and Hz for each generation of Intel Processors: https://www.intel.com/content/www/us/en/support/articles/000025675/graphics.html