I have no problem pushing my E4300 (800MHz bus chip) to 425MHz at 8x. The CPU hits a FSB wall at this point. Bumping the multi to 9x resulted in 3.51GHz with 1.505Vcore (BIOS). My cheap Kingston DDR2 800 ValueRAM is running at DDR2 954 with 5-4-4-9 timing. Could go higher with more Vcore, but I will need to upgrade the Big Typhoon to tame the HEAT.
The author should have used 1:1 divider to take the memory out of the equation. That's overclock 101. Again, I wouldn't put too much faith in that overclock review. There is no guarantee compatibility when dealing with overclocked memory.