When those Pentium Extreme Edition chips started hitting 3.6GHz and higher, the cumbersome liquid-cooling hardware required to keep them from overheating became a visible, noisy reminder that heat dissipation is a major challenge for system builders. The reason in a word is heat: The faster a chip runs, the hotter it becomes.

If you'll recall, both Intel and AMD have been laying the groundwork to get people away from thinking of raw megahertz as the primary indicator of processor capability. You might not need a PC with such a pricey chip now, but our testing found that for applications and scenarios that will put it to the test, Intel's new quad-core chip will give you an absolute boost in performance. At $999, the Core 2 Extreme QX6700 will likely end up in only the most expensive of desktops, but the fact is that the multicore revolution is fully upon us. We found that with certain applications, Apple's high-end designer box is faster. We suspect that professionals and forward-looking gamers will be most interested in quad-core chips, and of the pros, the digital-media editors might not want to get rid of their Mac Pro's just yet. And if you're still stuck doing only one thing at a time on your desktop, the QX6700's promise for single-application performance is large, as well. Don't let the 'Core 2' fool you (great job, Intel Product Naming department), this new chip has four physical processing cores in it that make it a multitasking beast.

Welcome to quad core, by way of Intel's Core 2 Extreme QX6700. Barely wrapped your brain around dual-core processors? It only gets worse from here, folks.

Intel core 2 duo e4600 tdp