AMD Phenom 2 Processor

AMD had to overcome a few hiccups in the initial Phenom launch and revisit its pricing to stay competitive with Intel in the Core 2 era, but AMD's back in the game with the new Phenom II processor. It's not exactly a knockout blow, but the Phenom II X4 has the right price and enough performance to do some damage.

This year AMD will ship two new quad-core Phenom II X4 processors, the 940 Black Edition and the 920, clocked at 3.0GHz and 2.8GHz, respectively. Black Edition processors come with an unlocked multiplier setting to make overclocking easier for PC enthusiasts. The processors differ only in clock speed, and have identical specifications otherwise. The Phenom II X4 processors will come with 64K of L1 instruction and 64K of L1 data cache per core (512KB total L1 per processor), and 512KB of L2 data cache per core (2MB total L2 per processor). The processors will also have a shared 6MB L3 cache and will feature an onboard DDR2 memory controller with 17.1 GB/s of memory bandwidth.

Built on a 45nm manufacturing process, the processors will have a relatively cool maximum thermal-dissipation value of 125 watts. Cool 'n' Quiet 3.0, AMD's power-management solution, keeps the Phenom II X4 chilly during periods of inactivity. AMD states that the CPU will now use 50 percent less energy while idle in comparison to Cool 'n' Quiet 2.0.

In a move sure to make existing Phenom owners happy, Phenom II X4 processors will be backward compatible with existing AM2+ motherboards. Motherboard manufacturers will release BIOS updates to ensure compatibility. As a follow-up in early 2009, AMD will release AM3 socket-based Phenom II X4 and X3 processors. Both will also be backward compatible with current AM2+ motherboards and will support both DDR2 and DDR3 memory.

AMD also bundles the Fusion and Overdrive utilities with the processors. Fusion helps to improve gaming performance by disabling scores of Windows services and slightly overclocking the entire system. AMD's Overdrive utility helps to automatically overclock the system and lets users apply those settings on an application-specific level. Overdrive helped bumped our Black Edition up to a final speed of 3333MHz when we tried it out.

The new Phenom II X4 processors will be available immediately in quantity. Expect to find the Phenom II X4 940 Black Edition retailing for $275, and the Phenom II X4 920 at $235.

From the pricing angle, the best direct competitor to the Phenom II X4 940 Black Edition is Intel's 2.66GHz Core 2 Quad Q9400, a quad-core processor with 6MB of L2 cache. Intel's Core i7 920 sits at a similar price point, but the total cost of ownership is much higher for the i7 after you factor in the cost of the motherboard and memory. The i7 processor requires DDR3 memory and a motherboard with an LGA 1366 socket. DDR3 memory costs roughly twice as much as DDR2. AM2+-based motherboards start in the $50 range and cap off at $200, whereas LGA socket 1366 boards start at $200 and can run as high as $400.

We didn't have Intel's 2.66GHz Core 2 Quad Q9400 processor on hand for our comparison. Instead, we clocked our Core 2 Extreme QX6800 with 8MB of L2 cache down to 2.66GHz and put it up against the Phenom II X4 940 to see how the chips stack up.