[GMcDougal]

ok, ive googled and cant find the answer. everyone says this card scales better than the next, what does this mean? Also, how does a 4890 scale?

 

[Infrabasse]

This is how efficiently they work in pairs or triple setups, SLI or Crossfire

Idealy and providing their is no bottleneck on the PCI express speed available or the CPU speed, adding a 2nd card will bring 100% more performance, but this is never the case.
Some cards scale very poorly @ 30% others very nicely @ 95%, but this mostly depends on drivers and game optimisations.

 

[GMcDougal]

thanks for the reply. how does 4890 scale?

 

[rico2001]

When people say "scaling", they are referring to how well (2) cards do in crossfire compared (scale) to (1) card and/or (3) cards in crossfire compared to (2) cards in crossfire.

Here is a fairly decent review on multi-gpu 4890's:
Ultimate Heavy-Weight Fight: Radeon HD 4890 CrossFireX vs. GeForce GTX 285 SLI

 

[Infrabasse]

This depends on games and drivers, it can scale very well.
Reviews will tell you more than I can.

 

[waqasr]

It means how well they work together in pairs, or triples, basically more than one. Any normal person would think that if you were running for eg 2 4890s instead of one, you would always get double the frames with what you would get with 1 4890. But this isnt true, you can get anywhere from 5% to 90% increase in performance. There are known cards for crap scalling like the 9800gx2 in quad sli and there are cards which are extremely good at scaling such as the new ati 5770.