So I'm about to buy an ASUS R9 270 for my new rig (not the "X" because I've done some digging and I've seen that there is marginal difference in performance as it just is an underclocked version of the 270x and while both overclocked the 270 performs the same or even better and as I am planning to oc that makes it the deciding factor). I was wondering that down the line when I do buy another 270 and overclock them in crossfire, will the overclocked 270x crossfire be giving me more performance? I heard that the overclock depends on the 2nd gpu which will be on a 8x slot instead of a 16x one. Does the 270 ocd continue the trend in crossfire compared to it's 270x counterpart?