PCMark04 makes use of some fairly common desktop computer tasks for its benchmark metrics, although with its weighted scoring scale, it is still to be considered more of a synthetic benchmark.
Source - FutureMark White Paper - "The CPU test suite is a collection of tests that are run to isolate the performance of the CPU. There are nine tests in all. Two pairs of tests are run multithreaded - each test in the pair is run in its own thread. The remaining five tests are run single threaded. These tests include such functions as file encryption, decryption, compression and decompression, grammar check, audio conversion, WMV and DivX video compression."
The P4 560 takes the lead here with its overall clock speed advantage in the field. Additionally, it's a complete sweep of this test by the P4 lineup versus the Athlon 64 lineup.
Source - FutureMark White Paper - "The Memory test suite is a collection of tests that isolate the performance of the memory subsystem. The memory subsystem consists of various devices on the PC. This includes the main memory, the CPU internal cache (known as the L1 cache) and the external cache (known as the L2 cache). As it is difficult to find applications that only stress the memory, we explicitly developed a set of tests geared for this purpose. The tests are written in C++ and assembly. They include: Reading data blocks from memory, Writing data blocks to memory performing copy operations on data blocks, random access to data items and latency testing."
In the PCMark04 Memory test, the Athlon 64's integrated memory controller allows it to surge ahead of some of the fastest Pentium 4s. However, the P4 EE 3.46GHz CPU, with its 1066MHz FSB, shows a clear advantage over all others, even the top-end Athlon 64 FX-55. PCMark04's memory read/write operations obviously favors the higher-speed system bus of this new Extreme Edition P4, as expected.