Valve Software held their third hardware editor's day recently where they discussed Multi-Core CPU Processing in Source.
The next method which Valve tested was more difficult than Coarse Threading. The idea of this method is to take many identical tasks (data operations) and divide the work across all of the cores on the CPU.
For instance, you have 1000 operations which need to be completed ? it simply delegates those operations to each core. So for the new Intel Quad Core processor, 250 operations are sent out to each core for completion. This type of threading scales well which is good news for future processors which come with 8 or 16 cores (and more) but at the same time it is difficult because Valve must make sure that each operation is completed on time by each core as that data may be required by another core and so on.
TweakTown
For instance, you have 1000 operations which need to be completed ? it simply delegates those operations to each core. So for the new Intel Quad Core processor, 250 operations are sent out to each core for completion. This type of threading scales well which is good news for future processors which come with 8 or 16 cores (and more) but at the same time it is difficult because Valve must make sure that each operation is completed on time by each core as that data may be required by another core and so on.
TweakTown