Putting it all together
So far, we've quantified performance per dollar and relative value across a wide range of applications. We also wanted to come up with an aggregate score that distilled those results into a single scatter plot for easy reference. This aggregate score is by no means the be-all and end-all of processor value propositions, but it summarizes the results we've stepped through on the preceding pages. To generate this value score, we averaged the percentage performances of each CPU against our Athlon 64 X2 3600+ baseline. Each application's performance was weighted equally. We also left the render energy results out of this calculation, since that measure of energy efficiency is quite different from a benchmark score.

It would be unwise to draw too many conclusions based on this aggregate score alone. (You didn't skip ahead to this page, did you?) This sort of accumulation doesn't give us a singularly authoritative number to quantify CPU performance, but it does give us a good idea of how chips handle overall across our test suite.

Unsurprisingly, we see the same five chips come out on top as in many of our isolated tests: the 3600+, E4300, 5000+, 5600+, and E6600. We should, however, point out that the 4400+, E6400, and 6000+ sit very close to their respective competitors on our scatter plot, so they're not necessarily bad choices—they're just not the best. If you do a lot of 3D rendering and select the 6000+ for your own PC, for instance, you shouldn't sacrifice much in terms of overall performance compared to the E6600.

Among quad-core processors, the picture is much clearer. The Q6600 is quite obviously the most sensible choice compared to both AMD's underperforming Quad FX chips and Intel's overpriced Core 2 Extreme offerings.

Conclusions
After running 16 processors through a lengthy round of testing and analysis, we finally succeeded in unmasking the "final five"—the five chips that offer the best overall performance per dollar across our tests. If you haven't been paying attention, those are the Athlon 64 X2 3600+, the Core 2 Duo E4300, the Athlon 64 X2 5000+, the Athlon 64 X2 5600+, and the Core 2 Duo E6600.

This discovery shows that repeated price cuts have actually helped AMD's processor lineup remain competitive on the value front, even in the face of Intel's own price reductions and the launch of the $113 Core 2 Duo E4300. Whether AMD can keep this up until the rumored November-December release time frame of its Phenom chips remains to be seen, however.

Aside from our final five, Intel's Core 2 Quad Q6600 receives an honorable mention for being the best overall choice for users more focused on performance than on saving money—though still concerned about both. $530 is a fair amount to spend on a CPU, but the performance divide between the Q6600 and dual-core offerings is large enough to justify that premium for pretty much any performance-conscious user. In the same playing field, AMD's Quad FX platform fails to impress, and Intel's quad-core Core 2 Extreme chips are just too expensive. A word of caution, though: a number applications still don't benefit from the Q6600's extra cores at all—games and LAME MP3 encoding come to mind—so this chip isn't a performance panacea for everyone.

So there you have our first look at the performance per dollar of today's CPUs. Considering the heated price war currently raging between AMD and Intel, we expect this subject to be one we'll revisit in the future.