It depends on what version of CPU-Z would be used... I believe when I saw an overclocked Nehalem system, it did not show a 533MHz clock, but rather just the 133MHz FSB (QPI).
Intel works very close with the CPU-Z developer, so I assume if you see a version not yet released, it might be accurate.
Intel works very close with the CPU-Z developer, so I assume if you see a version not yet released, it might be accurate.