Memory performance
We generally start out with some memory subsystem tests, so we can see how the processors match up on that front. These results sometimes help us to understand some of the later benchmark results from real applications.

The Athlon 64's on-die memory controller gives it a very low latency path to memory, and the X2 is no exception. This low-latency connection also yields lots of memory bandwidth, giving the X2 a bandwidth edge over the Pentium Extreme Edition 840 and the Pentium D.

In the Linpack graph, we can "see" the size and performance of the CPUs' different cache configurations. The Pentium 4 processors with 2MB of L2 cache really stand out here, of course. Notice also that the Athlon 64 X2 4800+, which runs at 2.4GHz, matches the Athlon 64 FX-55 2.6GHz in L2 cache bandwidth. Like I said, AMD's 90nm chips appear to have faster L2 caches, clock for clock. You can also see how the X2 4200+'s smaller cache slows its performance with data sets of certain sizes.