Carmack Speaks at AMDZone.com
AMDZone has a summary of Carmack's two hour heart-to-heart at Quakecon. In that time he gave his thoughts on a broad range of industry topics, from Physics Cards, Multi-Core CPUs and the ATI/AMD merger to name a few.
"Multicore/multithreading he does believe that there is more benefit to it than widening SIMD. He sees the end to the great CPU clock up, and that threading is the way to go. They have had success to using threading with graphics renderer, but can improve it. Sound is another good possibility. The process of multithreading is difficult, but there are benefits. But when you can only thread 20% of a game you do not get a huge increase in peformance. Multicore consoles and computers means the work must be done however."
