In games the situation is even more evident: i925XE platform is completely defeated by the i875P based platform, even though the new platform supports faster system bus and the memory subsystem with higher bandwidth.
Summing up this mini test session I would like to state one thing clear: LGA775 systems based on i925/i915 chipsets remain slower than the i875P based ones. This situation wouldn’t change even if we speed up the system bus to 1066MHz and use the new i925XE chipset. DDR2-533 SDRAM still features pretty high latency, which causes all platforms using it to lose in tests. However, things are not that dramatic yet for LGA775. The arrival of DDR2-533 SDRAM with 3-3-3-8 timings can change the situation completely. Although, no one knows yet when these memory modules will appear out here in mass quantities.
The 1066MHz bus turned out to be no panacea here. Just this bus itself ensures very low performance improvement, which doesn’t exceed 1%, even though only in case of 1066MHz bus all contemporary LGA775 chipsets work in the synchronous mode. Of course, it should be the fact that i925/i915 chipsets have been initially optimized for work with 800MHz bus. So, in i925XE they simply had to speed up the system bus, in order to ensure at least some slight performance improvement of the new Pentium 4 Extreme Edition processors, because their clock frequency potential has already been completely exhausted and the 130nm Northwood core didn’t allow any further clock frequency increase. That is why in the next generation chipsets aka Lakeport and Glenwood the 1066MHz bus may turn out much more efficient.