Post-processing will basically require such. HDR and blur affects are usally added after the frame has been completely rendered. If they had linked frambuffer, each gpu writing to mem, this is no big deal, but when having one main gpu with memorycontrol, and the rest as slaves to the first, post processing would take place entrirely on first gpu, or be very slow due to latency(final frame would be rendered to mem, then processed, would make no sense to pass it elsewhere).Originally Posted by hurleybird
@cadaveca: I was just in the shower when I had a "Eureka!" moment.
Wait for it....
Wait for it....
Who said that both rv770s need to write to the framebuffer?
However, IMC design is something that AMD excels at, so who knows. Designing a crossbar and scheduler and using ringstop links to each gpu would work wonders, I suppose, and would offer what you are after, but again, the pcb design is what holds that back. the cost would be easily more than double two single cards...and possibly $100 more than two cards...killing the $499 launch price.
ANyway, I've thought of all of this long ago, as has AMD/ATI. It might makes sense to try it out on a gpu who's back end is pretty tight, but I don't see it possible until another gen or 2. 2 gpu's aren't enough to see a real benefit, but 4 or more starts looking good...basically the same type of computing offered by the Cell processor would be possible. one Main gpu managing all teh work and doing post processing, one gpu for vertex processing, one for shaders, one for geometry.
Bookmarks