Question Six monitors and video card questions

Nov 16, 2020
Looking to finish buying the parts for my new build and I have some questions about it that I can’t seem to find the answer to. Your thoughts and perspective would be appreciated.

My current setup runs 6 monitors – all are 24 inch at 1080 P resolution. It runs using two EVGA GTX 650 video cards – 3 monitors per video card. When I game, I use only one of the monitors for gaming (while the other 5 have other apps open – such as browser windows, etc).
My setup has run perfectly with no issues for seven years, although its time for a new computer.

I have a new build I have almost finished buying the parts for – centered around the Ryzen 5900X. The only major component missing is the new video card(s).

I am willing to go up to the cost of a RTX 3080, or RX 6800 XT for this build.

My questions are:
1: If I buy the RTX 3080, can I run it alongside one of my GTX 650’s to run my 6 monitors? Or will there be driver problems because I have two video cards in there from very different generations – even though they are both NVIDIA cards? Or do I need two of the exact same video card? I don’t want to have to buy two RTX 3080’s to run my 6 monitor setup as the cost would be too high.
Same question if I buy the RX 6800 XT. Would I have to buy two RX 6800 XT’s to run 6 monitors, or could I buy just one of them, and then buy a lower end $100 Radeon card to run the rest of the monitors?

2: If I buy the RX 6800 XT, can I run it alongside one of my GTX 650’s to run my 6 monitors? Or would there be driver/compatibility/stability/performance issues running one Radeon Card, and one NVIDIA card in my system at the same time? In other words can the two cards co-exist successfully/harmoniously? Or better to go with both video cards being from AMD or NVIDIA?

3: If I buy the RX 6800XT, can the AMD software run my 6 monitors as well as the NVIDIA software has run my current setup?

I do have a slight preference to stay with NVIDIA, as I have had no driver issues with them with my 6 monitor display. It has all run perfectly for seven years.
But I am considering going the RADEON 6800 XT card because it is good value paired up with my Ryzen 5900X, and I might be able to get one on launch day. As opposed to potentially having to wait months for a RTX 3080. Although I am concerned about how to get my 6 monitor setup going if I go the Radeon route.

Any help would be appreciated. Thank you.