Not content with just one core being run at 100%, Valve now plans to fully utilize 2 or 4 cores in it’s games, depending on which chip you have.  [H]ard|OCP has a lot of info on how Valve plans to implement multi-core threading in it’s games, and this includes giving entire cores to AIs so your enemies will truly be working in parallel.
“We now have multi-core processors in the marketplace, but where does this leave the gamer? Valve Software, of Half-Life and Half-Life 2 fame, sits down with us to prove they are making huge headway in multi-core gaming.”

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