Now we'll bust out the freaky 3D graphs to get a closer look at the output from Cachemem's latency tests. To keep things interesting, I've colored the different block sizes depending on whether they fit into a processor's cache. Yellow is L1 cache; light orange is L2 cache; and dark orange is main memory.

You can see how the 800MHz bus benefits the Pentium 4 3.0GHz and 3.2GHz chips versus the P4 3.06GHz on a 533MHz bus. Despite its relatively slower front-side bus clock speed, the Athlon XP is also very quick getting to memory—especially the 3200+ with a 400MHz bus.