Si puedes hacer un crossfire 5870+5850, pero creo recordar que ira a la velocidad de la mas lenta (la 5850) con que supuestamente tendras el mismo rendimiento que tu crossfire 5850+5850.
The downside to mismatched cards is you get constant frame rate jitter, so your game is not going to feel as-smooth as two closely-matched cards. This is one of the technical reasons why ATI does not allow CF of cards from two totally different series: they want to minimize the judder you will experience, but give you the freedom to mix certain different cards.
