2.5 GHz - 2.9 GHz Processors

The Bottom Line: AMD's new Phenom X4 9850 is overpriced and outclassed compared with its Intel-based quad-core competition. If PC vendors can use this chip to make cheap systems (as they did with older Phenoms), we might have nicer things to say, but as a DIY part at this price, we can't recommend AMD's latest quad-core CPU.

Specs: Processor, AMD Phenom X4 9850

The Bottom Line: If you thought dual cores were over the top, get ready. Intel presents the Core 2 Extreme QX6700, a single CPU with four distinct processing cores. At $999, the first quad-core CPU will remain an enthusiast part for a while, but as a glimpse of the future, it's clear that clock speed is out and core counts are in.

Specs: Processor, Intel Core 2 Extreme QX6700

The Bottom Line: Intel's Core 2 Duo E6700 offers the best price-to-performance ratio we've seen in a desktop chip. For half the cost of AMD's top-of-the-line chip, you get identical if not superior performance and better power efficiency. AMD surprised us last year with its completely dominant dual-core chips, but Intel regains the crown with Core 2 Duo.

Specs: Processor, Intel Core 2 Duo E6700

The Bottom Line: AMD's Athlon 64 FX line has worn the desktop CPU performance crown for over a year. The king is dead. Intel's new flagship Core 2 Extreme X6800 not only hands AMD a defeat on all of our benchmarks, but it's also a more efficient, better designed chip overall.

Specs: Processor, Intel Core 2 Extreme X6800

The Bottom Line: AMD's new high-end dual-core CPU offers plenty of bang for the buck, outpacing Intel's Pentium 965 Extreme Edition, which costs $200 more. Sounds like a good deal, but wait to see what Intel's next-gen Core 2 Duo chips have to offer when they debut later this year.

Specs: Processor, AMD Athlon 64 X2

The Bottom Line: AMD's Athlon 64 FX-62 helps usher in the new Socket AM2 chipset, but incremental performance gains make AMD look vulnerable to Intel's next-gen chips, due later this year.

Specs: Processor, AMD Athlon 64 FX FX-62

Editors' Take: Overclocking might give it fits, but at stock speeds, AMD's new dual-core elite chip is as fast as we had imagined.

Specs: Processor, AMD Athlon 64 FX FX-60

Specs: Processor, Intel Pentium E5300

Specs: Processor, Intel Core 2 Quad Q8300

Specs: Processor, Intel Core i7 I7-920