Conclusions
The best thing I can say about the Phenom X4 9750 and 9850 is this: AMD is back in the game. The banishment of the TLB erratum to the history books is, of course, a welcome development, and the higher clock frequencies now available are a small but important step in the right direction. The Phenom X4 9850 Black Edition can't always keep pace with the Core 2 Quad Q6600 or the Core 2 Duo E8500, but it's close. AMD still hasn't caught up to Intel's 65nm "Kentsfield" processors in terms of overall performance or power efficiency, yet it has produced a credible alternative to those products. That fact, combined with aggressive pricing and the bold move of offering an unlocked upper multiplier on a $235 quad-core processor, has enabled the Phenom to grab our attention. We can finally say with confidence that if you have an existing Socket AM2 system and want to upgrade, buying a Phenom looks like a more attractive upgrade path than making the switch to Intel.

Around here, we tend to think in terms of guide-worthiness, in reference to our helpful system guides with specs for building a new PC. I think we can now say that the Phenom is also a guide-worthy proposition, if not as a primary recommendation, then at least as an alternate. The MSI K9A2 Platinum motherboard we used in our Phenom test rig sells for as little as $159 online and would make a nice foundation for a Phenom system—we're talking about a board with four second-gen PCIe x16 slots, a board capable of three- and four-way CrossFire X configs. AMD's so-called "Spider" platform has had an incredibly rough childhood, but it's beginning to mature into a reasonable proposition, believe it or not—not the fastest or the best in any sense, but a potentially solid value.

That, for now, is enough to get AMD back onto the PC enthusiast's radar and into contention in the middle of the market, thanks in part to the window opened up by the slow ramp of Intel's 45nm chips. The next steps for AMD may prove to be considerably harder, but they've at least established a toehold again.