Hello, does crossfiring double your GPU clock, shaders etc (i know it doesnt for memory) - like is it double performance (ie. fps should double in CF in games that support CF tech?).
6xxx series coming out soon, bought 5870 1 month ago (didnt know about 6xxx at time of purchase).
so should i:
1. buy another 5870 to CF, or
2. sell 5870 + buy 6xxx.
I want to know if 5870CF will still kick 6xxx's ass when it comes out.
First off, until the 6000 series is released and benchmarked it's hard to say exactly how it'll perform. However, you can fairly confidently say that 2 x 5870's will beat out a single 6000 series card almost without exception. Generation to generation, there's usually a 20% or so improvement in overall performance. Certainly not a 100% improvement.
If you already have a single 5870 (which is a stellar performer) I'd say you probably want to just get a second for Crossfire.
Just like 2 x GTX 260's perform equal to a single GTX 470, I imagine you'll see the same sort of thing with the next gen ATI cards.
Also of note, Crossfire doesn't equal a 100% increase in FPS. There's some loss overall with scaling. That all depends on drive tuning, and quite frankly the game you're playing. Some games get very little increase from Crossfire or SLI, while others get 90% or more improvement. You best bet there, is to determine which games are important to you and search Google for Crossfire benchmarks with that (or those) particular game(s).
5870CF is about 180% performance of a single 5870.
It should hold up pretty well to the new 6XXX series since its change isn't overly dramatic, and should at least be on par with the 6970 (5870 replacement).
However, the 68XX is launching next week and the 69XX is coming in November so I don't see a reason not to wait and see how the HD6000s features stack up against the 5870.