Need help with 3 monitor setup.

[MarkJohnson]

I had my old setup of 2x28-inch 4k monitors with a single 23.5-inch 1080p monitor. It was working okay, but at 3x times 1080p, so my RX 480 8GB was handling it just fine.

Well, I decided to replace the tiny 23.5-inch montor with a 27-inch monitor and it reset my whole display configuration to default true 4k with 3 separate monitors.

When I configured Eyefinity this time, my two 4k monitors were treated and a single monitor with the 1080p as a second monitor. When I finished, everything was in 4k resolution. Maybe the 1080p was dynamic resolution? I'm not sure.

So, I now want to get back my 1080p mode across all monitors again, as now my game lags and stutters a lot and only get 17-25 FPS.

Also, does this game support crossfire or SLI? Maybe a second RX 480 will help a lot? I can't afford one for a couple of months, so I'll need 1080p mode enabled in the mean time.

I play at max (Ultra) settings, so maybe I can get some of my smootheness bacvk iof I lower my settings there as well.