Memory performance
So how does DDR2 memory handle, and does the 925X chipset offer much performance advantage over the 915G?

Well, well. The old 875P chipset with DDR400 memory comes out on top in the memory bandwidth sweeps.

Linpack shows us a visual of how fast the CPU can compute data matrices of various sizes, from those stored in the on-chip cache to those that only fit into main memory. Unfortunately, in the case of the Pentium 4 Extreme Edition chips, their 2MB L3 caches can hold any data set Linpack throws at them, so we don't get a look at main memory performance. The Pentium 4 560, though, nicely outpaces the 875P system in Linpack, showing us a hint of better performance from DDR2 memory after we get into data sizes larger than its 1024K L2 cache.

Here's a surprise. For some reason, I half expected DDR2 memory to have higher access latencies, but that's not the case. The Pentium 4 Extreme Edition takes longer to get to memory on the 875P chips than on then 915G and 925X. Then again, it's all very close, and the tables are turned with the Prescott chips, where the 875P shows slightly lower access latencies.

No surprise that the AMDs are fastest, though, in overall memory bandwidth and access latencies. The Athlon 64's built in memory controller is very tough to beat.