If the launch of Intel's new quad-core Core 2 Extreme QX6700 processor has made one thing clear, it's that some applications are multithreaded, and others are not. Those that are can look forward to a healthy performance boost jumping to four cores, including near-linear scaling in some cases. Those that are not enjoy no such performance benefits, and may even run slower than on the fastest dual-core chips due to the slightly slower clock speeds of Intel's first quad-core offering. Unfortunately, most of today's game engines are among those applications that aren't effectively multithreaded. A handful can take advantage of additional processor cores, but not in a manner that improves performance substantially.

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