Can you use two different cards with crossfire?

[TooMuchButtHair]

For example, can I use a HD 3850 256MB and a HD 3870 512MB at the same time? I use in SLI you must use the same Nvidia cards (but different brands are okay), but what about crossfire? Now that ATI/AMD cards just got a sizeable price cut (that will take effect soon), I'm thinking about getting a 3870 now, and another card in a few weeks. For me, cheap = good.

 

[mep916]

Yeah, from what I understand you can. The 3870 would be forced to run at the speed of the 3850, however.

 

[oscaryu1]

And seeing as the 3850 can OC to around a 3870's speeds...

 

[Archangel]

and the onboard RAM of the 2nd card isnt used like in SLI i take it?

 

[mep916]

and the onboard RAM of the 2nd card isnt used like in SLI i take it?

That's a good question and I'm not exactly sure how the RAM is treated.

 

[Geoff]

That's a good question and I'm not exactly sure how the RAM is treated.

I believe the memory is mirrored, meaning that the same textures and data are stores on both cards. So for example if you had two 3850's in CF with 512MB of RAM each, then you still only have 512MB of VRAM even in CF mode.

 

[mep916]

I believe the memory is mirrored, meaning that the same textures and data are stores on both cards. So for example if you had two 3850's in CF with 512MB of RAM each, then you still only have 512MB of VRAM even in CF mode.

How does it work if you have one card with 512 and the other with 256? You have a total of 512?

 

[Archangel]

How does it work if you have one card with 512 and the other with 256? You have a total of 512?

thats what I ment, I think you might only have 256Mb then, if the memory is mirrored indeed