Conclusions
In the Phenom II, AMD has produced a chip that comes strikingly close to duplicating the performance of Intel's mid-range Core 2 Quad processors, the Q9300 and Q9400. The Phenom II proved to be faster in several of our gaming tests, but it was slower in some components of WorldBench, including WinZip and Photoshop, which lowered its overall score a bit. On the whole, though, the key characteristic we saw through the bulk of our performance tests was the remarkable parity between the Phenom II X4 940 and the Core 2 Quad Q9400—and the same between their siblings one notch down the ladder. The idle power use of our Phenom II X4 940 system was a couple of watts lower than its Core 2 Quad-based adversary, although it did draw 24W more under load, which was the Phenom II's one definitive disadvantage in this comparison. The Phenom II may even be able to rival the Core 2 Quad's vaunted overclocking headroom—and it's hard to argue with the ease of overclocking a Black Edition processor with a simple multiplier tweak.

Considering that the Core 2 Quad Q9400 was the featured processor in the "Sweeter spot" build in our latest system guide, the Phenom II puts AMD back in the running right in the middle of the enthusiast PC market, where price and performance converge in solid value. You still don't need (and probably won't benefit from) quad cores for gaming, but the Phenom II's individual cores are more than fast enough to perform well in games, in addition to the multitasking and multithreaded performance they can deliver in other scenarios.

With the Socket AM3 versions of the Phenom II looming so close on the horizon, I suspect many folks may choose to wait on building or buying an all-new AMD-based system. Current owners of Socket AM2+ motherboards may not wish to delay any further, though, and if they've been waiting to upgrade from something like an Athlon X2, well, I wouldn't blame them for making the leap now. Just remember that you're sacrificing an easy upgrade path to newer motherboards and DDR3 memory.

Some tough realities remain for AMD, but I'd say they're now tempered by a little more hope. Although the Phenom II is a marked improvement over the original 65nm Phenom, AMD still can't match the fastest Core 2 Quads in clock-for-clock or outright performance. And obviously, the Core i7 is yet another step beyond the Core 2. With Socket AM3, though, AMD should have an infrastructure in place that's very much like the one Intel plans to introduce with the upcoming Nehalem-derived mainstream desktop processors. AMD will then have plenty of knobs and dials to tweak on the Phenom II—memory speed, L3 cache frequency, and core clocks among them—to increase the performance or improve the power efficiency of its CPUs. I'm doubtful any version of the Phenom II will be able to take advantage of raw bandwidth like the Core i7 does in our scientific computing benchmarks, but higher speed grades could help. And, frankly, such applications aren't presently all that important for desktop PCs. Given all of that, the match-up between future versions of the Phenom II and the upcoming Core i5 (or whatever it's eventually called) might be a challenge for AMD, but it may not be Armageddon after all.