Geforce RTX 4090 Founders Edition with Four PG27UQR Monitors

[Christopher561]

Hello,

Hope everyone is doing well today.

I have a MSI Pro Z790-A  Mobo with a i9-13900KF and 850watt PowerSupply with 64 GB of ram, and a Geforce RTX 4090 Founder edition. Windows 11 Pro

I recently upgrade to all 4k Monitors, No real reason to I just wanted to.

I was previously running two 1920x1080 x 75hz monitors and two 1280x720 75hz monitors all with "extend desktop to this display" Enabled. worked great. I then Upgraded to Four Asus PG27UQR 4k 160hz 1ms Monitors. I used the 3 Display ports on my 4090 RTX and the one HDMI port, I can only get two of them to show a desktop. Under Display settings All Four monitors show as being found, I just cant extend the desktop onto more than two of the displays at once. 

I have tried Disabling Gsync, Resetting all settings on all monitors to default. Run Windows Update. Updated to the latest Nvida Drivers, I even tried older drivers with no help. I have tried Various resolutions all the way down to 800x600 to 1280x960 up to 1920x1089 all the way back up to 3840x2160 Iv tried all different refresh rates from 60, to 120 to 144 to 160... I have tried different cables, in different orientations Hdmi and Displayport. I have even tried different Monitor combinations two new 4k monitors with one old 1920x1080 75hz  monitor.  I have tried resetting, Tried one monitor install at a time. I even installed the Asus PG27UQR monitor driver. Im lost, Im hoping I dont have to return these. My only other Idea is to try another brand of 4k monitor and try something with 144hz. not 160hz. 

As the Specs state for the 4090:

4 - Multi Monitor:

• 4 independent displays at 4K 120Hz using DP or HDMI
• 2 independent displays at 4K 240Hz or 8K 60Hz with DSC using DP or HDMI
• Other display configurations may be possible based on available bandwidth

  I have even tried setting all the new 4k displays to 4k at 120hz which you would assume would work since The 4090 specs state that 4k at 120hz is supported.

  I am lost. And the odd thing is that even though the 4090 states that it supports 4- 4k monitors at 120hz, 4k monitors at  120hz are kind of hard to find.

  Please any Help is greatly apricated,

  Chris

[Christopher561]

SO I will admit I have seen this issue accross the 4090 forums online... I hope we can find a solution.

This is from someone on another forum..

2 - Use the 528.49 driver for your testing while you are working on this. 3 - Only use 60Hz for ALL Monitors. 4 - Make sure that all the Monitors are using the LATEST FIRMWARE and use CRU (ToastyX) to check the Internal EDID data and firmware to verify they are all IDENTICAL internally. Just because they are all the Same model does not mean they are identical. 5 - Not all cards are the SAME. Some have SHARED PORTS. These are generally ASUS / Gigabyte cards, but others can do the same...Check the Backplate for idents that indicate BLOCKS. (2)HDMI and (2)DP are generally grouped....using one set BLOCKS the others from being used. 6 - In the BIOS, disable rBAR. 7 - In the OS, disable the HAGS. Got no other suggestions to try.

Hope this helps someone. This did NOT I repeat did NOT solve my problem.

[Silent_Scone]

Hey,

Have you posted anything about this on NVIDIA's forum, I'm assuming you're not the only one looking for a solution? Fairly niche configuration, but understand the frustration.

[Christopher561]

Hey,

Yes I have,  Someone already recommended all of the trial solutions that I posted here. No luck 😞 going to try a deferent brand of 4k monitors with a slightly lower Refresh rate from factory (144hz). Maybe since the asus monitors are overclocked to 160hz they will not allow you to lower the refresh rate to something lower that will not interfere with the video cards limitations. the founders 4090 rtx should handle Four 4k monitors at 120hz. it says so in their specs. I think its because of the overclocked asus 160hz refresh rates.

I hope there are more solutions because these Asus monitors are beautifully!!!!!!!!!!! It would be a shame to send them back. Oh well cant win them all. 

[Christopher561 · Accepted solution]

Hi Everyone,

I have some sad news. And it is really hard to say this, I must return all 4 of the ASUS PG27UQR Monitors.  I have built many computers with ASUS components. Unfortunately this round I must return the monitors. I bought four new monitors winch i do not want to disclose the manufacture. They were 4k and 144hz monitors. Which are running at 4k and 144hz on the 4090 founders edition with all four operating at 4k.

It is what it is. 

ASUS's monitors were beautiful and well built just not compatible with what I had intended.

Have a nice day everyone!

Chris