5400x1920 @ 120 Hz, that's 10.4 megapixels.
I was able to drive my puny 2560x1600 (4.1 megapixel) display with decent GW2 performance at maximum settings with a single Radeon HD6970. My PC was pulling over 400 watts from the UPS and there was a lot of heat being discharged from the case while I was playing, but it played pretty decently. I didn't check the frame rate, but I'm certain that it was less than 60 fps.
i7-8700K, H100i v2, RoG Strix Z370-G Gaming, 16 GiB, RX Vega64, 960Pro SSD, 5TB HDD, Define Mini-C, SS-660XP2, C32HG70, RK-9000BR, MX518