http://bugs.winehq.org/show_bug.cgi?id=36399
--- Comment #26 from wineuser sickam@mail.ru --- The Autodesk Scaleform UI seems to cause an CPU bottleneck which is the reason for the low FPS.
http://www.reddit.com/r/GlobalOffensive/comments/1ynb0b/autodesk_scaleform_h... http://tera-forums.enmasse.com/forums/general-discussion/topics/TERA-UI-issu... unresolved?page=1
I think that this explains everything. I don't know if the CPU usage is higher on WINE than on Windows so if anyone could verify that it would help a lot.