Crossfire Question

[Ethan_Kaizer]

I was just wondering, is it okay to crossfire two different cards? I have heard that it works in most cases (Not sure about all). I have an HD 4670 now, and in the future, I might want to put a second graphics card in. I know I can put a second 4670 in, but would it be possible to maybe crossfire a 4670 and a 4830? What would the scaling be like? Any info or experience or tests on the subject would be nice.

-Ethan

 

[NosBoost300]

would not work... i think only older model cards (ie x1900xtx and x1900xt's and what not) were capable of doing so

so keeping it short and sweet.. negative

 

[baron5]

yeah i dont think you could, dont know alot about that sorry. unles the cards have identical memory,badwidth,frequencies etc. they will not work correctly.

 

[TheDiceman]

See, I never heard that ATI removed that option. As far as I last heard (I admit I do not pay a lot of attention to Crossfire and SLI requirements) was that with Crossfire you could have two different cards from the same series (ie both 3000 or 4000) but the higher end of the two cards would be downclocked.

 

[meat_helmet]

See, I never heard that ATI removed that option. As far as I last heard (I admit I do not pay a lot of attention to Crossfire and SLI requirements) was that with Crossfire you could have two different cards from the same series (ie both 3000 or 4000) but the higher end of the two cards would be downclocked.

No because not all the cards in the same series have the same cores, memory etc. A 4670 is very different tech to a 4870. Its not just a matter of changing clocks.

 

[zmatt]

They have to have the same gpu. If you have 2 4850s from 2 different manufacturers you will be ok.

I just checked wiki, in CrossfireX you can have different cards as long as they are in the same family.

ie: 48XX cards.

 

[Ethan_Kaizer]

They have to have the same gpu. If you have 2 4850s from 2 different manufacturers you will be ok.

I just checked wiki, in CrossfireX you can have different cards as long as they are in the same family.

ie: 48XX cards.

Aww man so I can't do a 4670 and a 4830 :\

Well, 2 4670s should be fine for a while.

 

[Peter.Cort]

yeah, crossfire doesn't work like sli where they clock down to the lower settings. basically crossfire does like one pixel from one card, one pixel for another and etc.. sli splits the frame up into halves and has each card render half of the screen.

at least i believe thats how it works, or it might be the other way around.. i forget.. but i know you can crossfire with different cards, justa s long as they are in the same family.

 

[meat_helmet]

Really...ok ill eat my words... I thought it wasnt possible.

Still, most of the time it wouldnt be worth it as having one card clocked down may in many cases negate the point of having xfire.

 

[zmatt]

yeah, crossfire doesn't work like sli where they clock down to the lower settings. basically crossfire does like one pixel from one card, one pixel for another and etc.. sli splits the frame up into halves and has each card render half of the screen.

at least i believe thats how it works, or it might be the other way around.. i forget.. but i know you can crossfire with different cards, justa s long as they are in the same family.

Nah, they have scissor, AFR and Checkerboard. They don't do per pixel.
Scissor cuts the frame in half and each do one half

AFR is alternating each doing the other frame

and Checkerboard as the name implies breaks the frame into several blocks. One card does one group and the other does the second group.

And TBH I don't see any real advantage in sli allowing you to use two different cards. It slows the faster one down so you get the performance of buying two cheaper cards while having spent the cash on a more expensive one.