Futuremark PCMark04 - CPU and Memory Benchmarks
To get an idea of how each PCMark04 module calculates its score, we've taken a quote from FutureMark's support documentation.
"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."
Looking at the performance results, the dual-core Pentium D 820 demonstrated a sizeable lead over the Pentium 4 630 and 530J, both of which are clocked 200MHz higher than the 820. What's important to note is that the CPU test is designed with some multithreaded operations, allowing the Pentium D 820 its lead. What is less important is the L2 cache complement as seen when comparing the Pentium 630 with 2MB vs the 530J with 1MB. Rounding out the numbers was the Athlon 64 3200+ with 1MB L2 cache.
"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 this test the scores were more balanced, with the Pentium D 820 recording the slowest results of the three Pentium-class chips. What appears to be the main benefit in this test is cache density and clock speeds. The 3200+ with its integrated memory controller closed out the test quite a bit slower than its Pentium counterparts.
While synthetic testing is good at giving us an idea of how a piece of hardware should perform theoretically, to get a clearer picture we need to run more intensive real-world tests.