G4 upgrades

I have recently upgraded my work G4 533 with a Sonnet 1.4ghz and it runs awesome. It was a major improvement... now I decided to put the old 533mhz into my sawtooth 350 at home.

Which I did knowing that the system bus speeds where different. The 533 was on a 133 bus while the 350 is on a 100.

The improvement is quite noticeable it really feels like I am running at 533 but my system profiler reports a 400mhz clock.

How can I tell if this is accurate? Is the system profiler accurate all the time? It really feels like a bigger improvement than just going from 350 to 400?

thanks

-b