You probably have read some Core 2 Quad Q6600 and Athlon 64 FX-70 reviews already and  found, in a nutshell, is that four processor cores is a wonderful thing to have, but only if you have some heavy multitasking to do or you happen to make extensive use of one of the few applications out there capable of taking full advantage of four cores simultaneously. But things have changed a bit - the availability of cheaper-err, less expensive-quad-core options like the Core 2 Quad Q6600 and Athlon 64 FX-70. That's why TechReport decided to take another look at the desktop quad-core solutions. Here's an excerpt:

When the Quad FX platform first debuted, we were disappointed with its very high peak power consumption and its lack of cheaper, more power-efficient motherboard options. We also had some concerns about whether a NUMA platform was being used optimally in Windows XP. Now, time has passed, Vista has debuted, and we've gotten our hands on a pair of FX-70s, but not enough has changed. We were right to suspect that the lower speed grade Quad FX processors might not have the outrageous peak power consumption of the FX-74s. The FX-70s are much tamer on that front, to the tune of roughly 130W less. But Vista's NUMA-aware kernel hasn't allowed Quad FX to gain much, if any, performance ground on Intel's quad-core processors. And the nice-sounding idea of a pair of FX processors for $599 doesn't truly translate into a good value for a quad-core system. In fact, moving up to a Q6600-based system is worth every penny of the extra hundred bucks or so. As much as we like the idea of a dual-socket platform for PC enthusiasts, Quad FX isn't likely to gain any traction unless and until we see some more reasonable-in every sense of the word-motherboards for it. Here's hoping somebody comes out with a Quad FX mobo that has the admirable power efficiency of Opteron systems before AMD scuttles the Quad FX concept entirely.

Meanwhile, Intel's quad-core processors are just amazing. Their performance doesn't seem to be significantly impacted by a front-side bus bottleneck, contrary to what one might expect. They typically scale up to four threads at least as well as Quad FX systems. Their power use is restrained, and as we anticipated, the Core 2 Quad Q6600 looks to be even more power-efficient than the Core 2 Extreme QX6700. In fact, the Q6600 proved to be the most power-efficient processor in our render energy test, beating out dual-core chips in the process. That's poster-boy-type behavior for the multi-core revolution.