How does crossfire work?

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I can tell you how exactly SLI works... It works 2 ways depending on how the game is coded.

Split Frame Rendering, The top half of the screen is rendered by one card while the bottom half is rendered by the second card. In most cases when you have a skyline, the top half of the screen has less detail than the bottom half. In those cases the cards will shift the screen 60/40 to even the workload.

Alternate frame rendering, it's very simple... Frames 1,3,5,7 etc are rendered by one card, while frames 2,4,6 etc are rendered by the second card.

In theory, this would double the performance but since the Top (master) card has to do any of the final rendering this lowers the performance a little. I don't know exactly how Crossfire works, sorry.



What the guy said above me is correct. The GPU pretty much has to match and so does the memory. You can X-Fire a 6970 with a 2gb 6950 but... the 6970 would get downclocked to match the speed of the 2gb 6950. At this point, the extra money spent on the 6970 would be wasted. The memory size has to match. You can also crossfire a 6990 with a 6970, that would technically give you 3-way crossfire.

Usually you will see up to an 80% performance boot by Crossfiring two cards. Sill, running two cards like the 6750 in Crossfire is pointless since it brings your performance up to 6870 levels at best.

You can never crossfire a 6900 series card with a 6800 series card.

Only the AMD FM1 platform gives you the ability to crossfire the onboard 6550D with another lower end card. For example, with the A8-3850 APU processor you could add a Radeon 6670 graphics card and Crossfire that with the onboard 6550D... giving you the 6690D2 graphics solution. This has almost the same power as a 6770....Show more

Crossfire takes two graphics card of the same chipset, syncs them, and uses both cards simultaneously to render the image on your screen.

You cannot Crossfire onboard graphics with a 5770 unless the two have the same GPU chip....Show more