Crossfire implementation

Differences between Crossfire and SLI

While ATI and NVIDIA’s multiple graphics card technologies share some key concepts, there are also a number of differences between ATI’s and NVIDIA’s implementations.

For starters, the most basic difference between ATI Crossfire and NVIDIA SLI is that ATI has a dedicated CrossFire card designed just for linking to your existing ATI X800/X850 series graphics card. For now, ATI provides two different CrossFire boards, a RADEON X800 Crossfire Edition, and a RADEON X850 Crossfire Edition.

As their names imply, the RADEON X800 Crossfire Edition supports the X800 series of R420 and R430 VPUs, this includes the RADEON X800, X800 XL, X800 PRO, and X800 XT/X800 XT Platinum Edition. ATI lists two SKUs for the X800 CrossFire board, one with 128MB of memory and a second with 256MB, but we think the 256MB board will probably be the predominant solution. ATI’s RADEON X850 Crossfire Edition ships with 256MB of memory and supports cards based on the R480 VPU, this includes the RADEON X850 PRO, X850 XT, and X850 XT Platinum Edition.

Since the X800 Crossfire supports R420 PCI Express boards launched nearly a year ago, ATI claims that Crossfire already supports nearly 1 million people that are “Crossfire-ready.”

NVIDIA, on the other hand builds their SLI technology into the graphics core of every GeForce 6600 GT and 6800 series card, the user merely needs to purchase a second PCI-E NVIDIA GPU in order to take advantage of SLI. Purchasing two X850 boards wouldn’t give you Crossfire, you’d merely have two distinct X850 cards which can’t be linked together.

ATI CrossFire Pricing
CrossFire Edition Card	Estimated Price
RADEON X850 CrossFire Edition (256MB only)	$549
RADEON X800 CrossFire Edition 256MB	$299
RADEON X800 CrossFire Edition 128MB	$249

While ATI has given us pricing for CrossFire X800 and X850, at Computex this week they’ve been adamant that the pricing data they’ve given above is merely preliminary. In other words, the prices you see above may, or may not change by the time the first CrossFire cards are available in July. While we weren’t told this by ATI, we believe ATI’s final pricing strategy for Crossfire will ultimately depend on NVIDIA’s upcoming next-generation GPU, codenamed G70. Quite simply, if NVIDIA is able to deliver G70 on time and with good performance, ATI will likely feel the need to lower prices on CrossFire boards substantially.