What kind of resolution is that? I divide 3440 by 3 and do not get a whole number, lol!
It will handle 5760x1080. Now, 7680x1440 (3 2560x1440 monitors), you will absolutely have to turn down settings on many titles and run without AA. There are more pixels there than with 4K UHD amd the 1080 is barely a 4K card..
This is assuming you are gaming. If you just want a picture on three screens, it will do that.