Question about Gigabyte Aorus FV43U

When using the PBP functionality, do you get two small 1920x1080 or two tall 1920x2160? My current 32" BenQ only give me the first option and it is next to useless. However, I can not find any entry for 1920x2160 in the manual that I found online so if anyone could confirm this, it would be very helpful.