AMD repeatedly noted the capability of R600 video card for accelerating physics in games, and products on base of chip r600 with their standardized shader architecture in this plan has large hopes. AMD began to demonstrate motherboard with three slots PCI express x16: two video card will be occupied by graphic acceleration in mode crossFire, the third will accelerate physical effects. Many of the potential users of this technology by the inertia thought that also for “physics” was necessary equivalent with other video card.
Associate note that AMD support the concept asymmetric physics, when two video cards are occupied by graphic acceleration and another with physics acceleration  , in this case video card can relate to different generations and have different performance level . For example, it is possible to organize configuration with two video card series radeon HD 2000 and video card series radeon x1900. The first will accelerate graphic, the second - accelerate physics. User will obtain supplemental advantage when updating its old video card , there is no need to sell it. ;-)
Asymmetric acceleration physics mode has been already supported by catalyst drivers  . And this allow to compensate the modest performance of video card radeon HD 2600/2400 in  physics tasks , in this case a second more powerful video card will be used in physics acceleration  . User can distribute roles between video cards in accordance to application priorities.