http://bugs.winehq.org/show_bug.cgi?id=11364
--- Comment #21 from Nikolay Sivov bunglehead@gmail.com 2009-11-24 09:11:12 --- (In reply to comment #20)
Wine 1.1.33 has become much better in running WinRAR (641 in UP mode, 961 in SMP mode), but still WinRAR only uses 160% out of two CPUs (in theory it should use close to 200%).
Try with current wine from git repo. Commit http://source.winehq.org/git/wine.git/?a=commit;h=a764fe89212500b0ffa23fa9a9... should probably fix this.