No Surprise: Intel Takes The Performance Crown, AMD Represents Value
The raw data makes it pretty clear that Intel's Sandy Bridge, Sandy Bridge-E, Ivy Bridge, and Nehalem micro-architectures are clearly faster than AMD's highest-end models. Even though we're missing Piledriver-based chips right now (again, they're going to be added soon, along with some older Core-based chips), benchmarks we've already run show that the flagship FX-8350 goes up against Intel's Core i5-3570, not its faster Core i7s.
There's no way around it: if outright speed is your top priority, and you have some money to spend, Intel wears the crown. From about $250 to $1050 or so, AMD simply cannot compete. Anything pricier than that and you're out of the desktop market entirely.
The silver lining, of course, is that AMD's FX processors do handle threaded applications fairly well. Even though they use quite a bit of power, a combination of modest performance and low cost is attractive to power users on a budget.
Lower-end Athlon II and Phenom II models are respectable in their own right, too. Depending on the applications you're running, screaming frame rates and lightning-fast transcodes may not be as important. For basic desktop-oriented productivity, you can get away with a dual-core CPU and spend very little. The quad- and hexa-core models are decent performers as well.
As you ascend the hierarchy of speed, each percentage point of performance costs increasingly more. Just look at the difference between a $320 Core i7-3770K and $1030 Core i7-3960X. If you're looking for a sweet spot in Intel's line-up, we're still fans of the Core i5-3570K at $215. The Core i5-3470 at $200 isn't bad either, though an unlocked multiplier ratio on the K-series part is easily worth $15 on its own.
In AMD's line-up, an FX-8320 might be your best bet for a desktop PC with discrete graphics. That's one of the models we plan to add shortly. At $180, it looks like a decent alternative to the FX-8350 at $220 or FX-8150 at $190. If your graphics requirements are more modest, and you don't need to spend extra on an add-in card, the A10-5800K is AMD's one Trinity-based APU that tends to do everything better than the previous generation. Selling for $120, it's good enough to warrant a look.
If power consumption is a major concern, it'd be hard to generalize and recommend one vendor over the other. Intel and AMD both offer low-power parts capable of going easy on your electricity bill. The former has its Sandy Bridge-based Pentium G630, Core i5-2500T, and Core i5-2400S processors that we tested, while the latter has the Athlon II X2 240e and Athlon II X2 250.