At the moment I am running a single Radeon HD7770 and am looking for an upgrade on a bit of a budget.
I can now buy a second HD7770 or a HD7950 or a GTX660. With the 7770 being quite cheap now, I wonder if the extra ~100 euro is worth it.
I have been reading that with crossfire you get quite an improvement of running a single card setup, so what would be the better choice? a second HD7770 or a single HD7950 or GTX660?