I don't think that this can be done in a reasonable way and even if it could, your computer would not be able to do DX11 gaming because the 4850 isn't DX11 compatible. This should be doable on a computer if you get a motherboard with a HydraLogix 200 chip and maybe one of a few other chips, but those are rare and usually expensive boards.
Thank you all very much, I Google'd it and found nothing.... So I obviously it was impossible lol! Anyone got a 7770hd for sale? Playing bf3 on high with one getting 30-40fps, but I want a tad bit more...
Hey, man, what if he got a HydraLogix board? He could totally rock the two together. Joking aside, CrossFire isn't supported cross series(HD5xxx and HD6xxx, for example).
That's what I was referring to.
Do you find HydraLogix funny? It can pair two of ANY graphics cards so long as one of them has an NF200 chip or the motherboard has an NF200 chip. Heck, you could pair a GTX 295 and a Radeon 6970 or some other wacky combination that way if you wanted to. The motherboard link that I gave has one such chip.