Setup:
2 Computers:
Intel 6700K CPU on Z170X motherboard (iGPU disabled) with an AMD Radeon RX 6800XT FE GPU
AMD 5950 CPU on B550 motherboard (no iGPU) with an AMD RX 7900XTX FE GPU
Earlier this year upgraded 4 monitors from 1080P Dell monitors (U2417H) to 4 x 4K monitors (U2723QE) plus an LG 55" CX OLED TV connected via HDMI. The Dell monitors are MST daisy chained in a 2x2 config: 1 set of 2 connected to the video card via Displayport, and the other set connected via USB-C
Initially this was setup on my Intel system with the RX 6800XT video card: 5 x 4K monitors all able to be driven at the same time. My newer AMD system had the RX 7900XTX and was connected to 2 Dell U2417H monitors and the LG 55" CX OLED TV. Because the Intel system is starting to exhibit that the CPU may be starting to go, I swapped the computers and now the AMD PC with the RX 7900TXT can only drive 4 x 4K monitors at once, not all 5.
To be sure it was not an issue because the AMD system does not have an iGPU, I replaced the RX 7900XTX with the RX 6800XT card into the system and used DDU to clean the drivers and the RX 6800XT can operate / drive all 5 x 4K monitors on the AMD-based system, while the RX 7900XTX can only drive 4 x 4K monitors.
Can someone at AMD explain what is different that the RX 7900XTX can not drive as many high-res (4K) monitors as an older generation GPU?
As a footnote, I started back in 2010 with the ATI HD 5870 Eyefinity Edition card and driving 6 DisplaPort 1.2 Dell monitors on a single ATI / AMD GPU. I've since upgraded GPUs about 4 times and monitors twice. I'm no longer driving 6 x 1080P monitors, now 5 x 4K monitors. This worked up until the RX 6800 XT. Is this going to be gone now to the way of NVidia who could never support as many monitors as AMD? I also have a Nvidia 3080Ti FE card that I had in the system with the RX 7900XTX to benchmark against one another in ray tracing performance., Now I'm going to look at the NVidia multi monitor support and see if it can at least equal the RX 7900XTX. I've never liked Nvidia's handling of multi monitor, but with their extra feature-set, it now makes me have to consider them if the playing field has equalled in the matter of multi-monitor support.
