Thanks for the suggestions @mrk. Already tried both 60Hz and 120Hz and there's no difference, I'd also already tried 2/3 of the Displayports on the card, just tried the third and it's even worse! That does point to the ports potentially being the issue. Will have to grab a HDMI cable and try them next.
For giggles, this is the third port:
For giggles, this is the third port: