Does anyone have experience crossfiring different cards?

[Dark4ng3l]

I was thinking of getting a card to crossfire with my 5770 in the near future. I was just wondering how well it works if I have say a reference 5770 running at 900 cores with my hawk at 1035 core or if I used my 5770 with a 5750.

Most 57xx card went down in price this week but the hawk it still the same price and i'm not sure I want to pay the premium for another one. I know some of you must have tried crossfire with a 5850 and 5870 or a 5970 with a 5850 or something. Any problems come up?

This would probably be on an 890 board with both slots @ 8x and the cpu would probably be a Phenom2 overclocked in the 3.8 range.

 

[Apocalypse23]

I know for sure that cross-firing a 5870 with a 5850 results in no issues at all. I'm awaiting my 5970 to arrive before I can test cross-firing it with the 5870 and 5850. You pose an interesting question, I'm just not sure if it would work.

 

[Dark4ng3l]

Well it's supposed to work fine with different cards in the same family(ie 57xx 58xx) I was just worried that having one card that is say 40% faster than the other one would lead to stuttering or ''weird feeling'' uneven framerates.

 

[Apocalypse23]

Here you go, it's absolutely feasible to crossfire with your requested setup:

--source--> http://game.amd.com/us-en/content/images/crossfirex/CF_combo_chart.jpg

 

[Apocalypse23]

Well it's supposed to work fine with different cards in the same family(ie 57xx 58xx) I was just worried that having one card that is say 40% faster than the other one would lead to stuttering or ''weird feeling'' uneven framerates.

It's possible to overclock one of the lower clocked cards to match with the speed of the higher card, then run crossfire. Performance should be similar.

My mobo supported pci-e 1.0 and 8x slot 1 and 4x slot 2 in crossfire so my 5870 + 5850 performance was bad...but when I installed this setup, the 5850 automatically clocked to 5870 speeds and resulted in crossfireX. Guru3d or another review site conducted a 5870+5850 test, basically the 5870 downclocked to 5850 speeds to make up for the difference. I think you can down-clock or up-clock either card to match the core clocks...

 

[blanketyblank]

From the reviews I've read it really just depends on the game. In some games the performance of a 5770 with a 5750 is worse than with 2 x 5750, but in others it's in between 2x 5770 and 2x 5750 where it should be. That said not sure how different OCs would work with the same card, but probably would be better since you've got same number of shaders.