Define can't run? Crash in gameplay or can't load it up.
I can play crysis fine on my crossfire setup with the 4890's. Hell of a lot more stable than my old 4870s.. I just finished 12 loops at enthusiast 1900*1200 4AA on ambush and my OC seems stable so far
(I'll burn out another 12 or so when i get home from work)
At any rate, I can't be sure why you cant play crysis Rangers.. I do from time to time get a bug where the map loading freezes at 90%. Though that is a 64bit bug I think.. Securom has destroyed my 32bit (legit over steam) version.. so I have to use 64 (not that i wouldn't normally, still hate securom)
As for noise. During Folding I get some harmonic distortion. But that is a hum, not a clicking.
Check to see the fan is not hitting anything. If it is annoying return the card (xfx has the most amazing warranty and thsiwont be a problem). It shouldn't be worrysome if it is tollerable, is just an annoyance thing. You can always set the fan to 30% all the time
By the way I also have an XFX card (two of them)