1 $300 card or 2 $150 cards?

[gsx2ner]

What is the advantage of crossfire? Are 2 cheap vid cards going to out perform 1 mid card? I'm building my first PC and can't find anywhere comparing the two to one.

 

[rambostyrer]

Don't know about scaling for the 6790, in wich 2 costs 300$ exept for this chart

http://www.tomshardware.com/reviews/radeon-hd-6790-barts-gpu-geforce-gtx-460,2917-14.html

But 2 6850's performs much better than 1 6970 and costs about the same.

 

[jyjjy]

In general it is best to start with the best single card you can afford. Crossfire/SLI can have issues and be a headache and wont work in certain games. When looking at benchmarks keep in mind that dual gpu setups often have much less consistent minimum frame rates than comparable single gpu cards and minimum frame rates are more important than average in terms of whether or not a game will run smoothly.
For your budget I would recommend unlocking an HD6950 2GB.
http://www.techpowerup.com/articles/overclocking/vidcard/159

 

[gracefully]

Back in the radeon 5xxx series, two 57x0s would outperform one 58x0 (2 5750s > 1 5850, 2 5770s > 1 5870), but if and only if Crossfire works properly. I agree that scaling and multi-GPU issues might bite you in the butt, so best keep it to one powerful card rather that 2.

 

[swifty_morgan]

First it would be nice to know what resolution you're going to game at, then the rest of your hardware. No sense in over doing it. Next thing.... just because 2 lesser cards have similar or higher "numbers" than and "equivalent" higher end card does NOT mean they will perform similarly. The architecture of the cards are different giving different results in actual game play. If you judge "performance" in specified FPS you're missing the point of why higher end cards are there.