The benefits of the Athlon 64 are such that if you ask well-informed users that question, they're likely to scoff at you. If you want to know the details, we recommend you read one of our most recent processor articles, such as the test of the 3.8 GHz P4-570, which contains benchmark results and thermal loss measurements that paint a fairly clear picture. Here are the facts in brief:

• Intel has been doing battle against high thermal losses in the latest Pentium 4 Prescott since the beginning of 2004. Even though the parts are already being produced using modern 90nm technology, high leakage currents remain a problem. How well or poorly this can eventually be mastered is reflected in Intel's classification of the P4 in two thermal design types (PRB0 and PRB1). The first specification limits thermal design power to 84 W, whereas the latter is supposed to turn out up to 115 W of power. Only recently did 3.4 GHz P4 PRB0 models appear.
• While AMD's 130nm processors are no energy-saving marvels, either, they at least offer the "Cool & Quiet" feature. Provided you have the right Windows driver and BIOS support, this allows you to gradually lower the clock speed and the CPU core voltage at low load all the way to 800 MHz, which significantly reduces thermal loss.
• In terms of performance, AMD processors remain a step ahead of Intel models, despite the fact that AMD has only just now hit 2.6 GHz while Intel churns along at up to 3.8 GHz. This shows once again that clock speed alone isn't everything, and is the main rationale behind the "plus" some AMD processors sport after their names. For years, the label was meant to make it easy to compare Intel models (though AMD has tended to go overboard with the numbers game from time to time.)
• The AMD processor's integrated memory controller works more efficiently than Intel's conventional architecture. For that reason, the use of DDR400 memory (in dual-channel mode for double the bandwidth) represents no handicap whatsoever in terms of performance, and has the practical advantage that it currently costs less than DDR2-533 RAM.

Personal preferences are also a decisive factor in any CPU purchase decision, to be sure. After all, a Mercedes fan isn't likely to switch to BMW overnight. From a technical standpoint, however, AMD has been offering customers more for their money for months now.