AMD CPU: Phenom X4 9850 Black Edition (2.5 GHz) Retail AM2+

Current Cost: $235
Consecutive Guides: New
Price Change: N/A

In our previous guide, we had a tough choice between the 2.3 GHz Phenom 9600 quad and 3.2 GHz Athlon 64 X2 6400+ dual core processors, but we settled on the Phenom due to its superior multi-threading and unlocked multiplier. Now that AMD has released the updated B3 core and 50-series of Phenom models, the Athlon 64 X2 is not even a consideration, and we've also moved up the charts to the Phenom X4 9850 Black Edition.

The Phenom X4 offers a true quad core architecture, complete with 512K of L2 cache per core (2MB per CPU) and 2MB of shared L3 cache. It is a 65nm processor, with an onboard dual 64-bit (128-bit dual channel) memory controller that supports up to DDR2-1066. Now that the much-publicized TLB bug is a thing of the past, we recommend AMD buyers make the Phenom transition, especially as the Black Edition is fully unlocked and the newer Phenom X4 9850 BE offers higher overclocks than the older Phenom 9600 BE. AMD also includes a retail heatsink-fan with this 125W processor, for those that want to save some money.

The upcoming 2.6 GHz Phenom X4 9950 BE is another option (although at a whopping 140W TDP), as it should be appearing on retail shelves soon, and will be priced equivalent to our 9850 BE selection.

Intel CPU: Core 2 Duo E8500 (3.16GHz) Retail

Current Cost: $266
Consecutive Guides: New
Price Change: N/A

The last time out, we upgraded to one of the new 45nm Core 2 Duo models, specifically the 3.0 GHz E8400. At the time, supplies were still low, prices were a bit higher and availability of the 3.16 GHz Core 2 Duo E8500 was nonexistent. A lot has changed since then, allowing us to make a slight upgrade to the faster 3.16 GHz processor, and at only a slightly higher price than the E8400 was in our previous guide. The 45nm Wolfdale features 6MB of shared L2 cache, which ramps up performance compared to an older 4MB Conroe, and it's tough to ignore a 3.16 GHz 45nm processor priced at just above $250.

The Core 2 Duo E8400 and E8500 are both excellent values right now, and will supply high-end gaming performance to any system configuration. Quad core would be nice, but as gaming performance is still mostly clock-speed limited (especially when you're comparing similar core designs) the 3.16 GHz Core 2 Duo E8500 on FSB1333 only takes a back seat to the 3.2 GHz Core 2 Extreme QX9770. The 3.0 GHz Core 2 Duo E8400 is almost as fast, but since we had the extra budget, we moved up one level. Overclockers may want to save the cash and select a lower-speed Wolfdale, but for general use, the Core 2 Duo E8500 fits out budget perfectly.

AMD Heatsink-Fan: 3rd-party AM2/AM2+ HSF

Current Cost: $50
Consecutive Guides: 2
Price Change: $0

Although the Phenom 9850 BE is a "Black Edition", it still ships with a retail cooler, but we'll include a few 3rd-party heatsink-fan recommendations. There are several high-end options at the $50 price level, including the Scythe Infinity (left) and Zalman CNPS9700 NT (right), both of which have proven very popular with Phenom system builders and enthusiasts alike. Feel free to select a cooling solution that fits your own requirements, but these two models are affordable, mid-range cooling options that won't break the bank, and are widely available at most online stores. For those on a strict budget, even the $25 Arctic Cooling Freezer 64 Pro (up to 130W) will do in a pinch.

Intel Heatsink-Fan: 3rd-party LGA775 HSF

Current Cost: $50
Consecutive Guides: New
Price Change: N/A

Since we have a bit more money in the budget this month, we can finally afford a 3rd-party heatsink-fan for our Core 2 Duo. These 45nm models are much easier to cool, and even the bundled retail cooler will easily do the job, so it really comes down to personal preference. The Zalman CNPS9500 AT (left) is a popular choice, and fits right in with the $50 budget, but like our AMD selection the Arctic Cooling Freezer 7 Pro (right) will do the job for around $25. Feel free to go with a 3rd-party heatsink-fan of your choice, as this can be something you may need to tailor to individual tastes and requirements.