especially if you are going for assassins creed, it is an nvidia optimized games as is the new far cry that is coming next week. it destroys even the 970.
so your only options are to crossfire that with a used GPU for $125-150 or to get that 970.
I am using a similar monitor and it ran perfect with CF 7950's; however, it was hot and loud with the massive overclock i was using. just moved to a gtx 970. it is about equal in performance but the heat and noise is less.
the reason i am planning to do an upgrade is to play assassin creed unity, so you would personally suggested that 970 is better than 290x? not planning to crossfire
especially if you are going for assassins creed, it is an nvidia optimized games as is the new far cry that is coming next week. it destroys even the 970.