The Tech Report heard from a Chinese hardware site that ATI may announce a multi-GPU CrossFire based physics implementation at Computex:
Now, HKEPC says ATI is ready to announce a multi-GPU physics implementation that will also allow graphics cards to be paired to accelerate physics, but without requiring them to have the same GPU. Indeed, SLI requires two cards with the same graphics core, whereas HKEPC says users will be able to mix and match completely different ATI cards (e.g. Radeon X1900- and X1600-series models) to accelerate physics.
