ATI X1800 User Guide - Page 118

110 CrossFire™ Rendering Modes Alternate Frame Rendering (AFR) Mode In this mode, all even frames are rendered on one GPU, while all odd frames are rendered on the other. The completed frames from both GPUs are sent to the Compositing Engine on the CrossFire™ Edition card, which then sends them on to the display. By allowing both GPUs to work independently, AFR provides the greatest potential performance improvements of all the available modes. It is also the only mode that allows the full vertex processing performance of both GPUs to be combined. 1 PCI Express® Slave Graphics Card 2 Radeon® X1800 Series Master Graphics Card 3 Partial Frame Rendered on PCI Express® Slave Graphics Card 4 Partial Frame Rendered on PCI Express® Master Graphics Card 5 Final Rendered Frame on Display The main limitation of this mode is that it cannot be used in applications where the appearance of the current frame is dependent upon data generated in previous frames, since AFR generates successive frames simultaneously on different GPUs. In these cases, the SuperTiling or Scissor Mode is used instead.