Weird hex borders after playing several turns

[illathid]

So i've been having this issue lately where if I play on DX10/11 mode I'll get the really weird thick borders to the hexes as pictured. I've tried turning the settings all the way down, but it doesn't seem to do anything.

I've got two GTX 680's in SLI, for graphics if that's any help.

Thanks in advance!

 

[The_J]

Did you try to disable the SLI?
Does it also appear on DX9?