Core speed differs in CPU-Z and BIOS



For starters: my apologies if this belongs in overclocking. I figured it had more to do with reading core speeds accurately than it did with my overclock, so I've posted it here.

I have a C2D E6550 (2.33 GHz, 333.3x7) that I'd been running at 3.15 GHz (450.0x7) for the past year or so on a Gigabyte P35-DS3L. Until very recently, I hadn't had any problems reading my clocks accurately with CPU-Z.

A few days ago, I noticed that CPU-Z was reporting stock speeds (333 MHz bus speed instead of 450). As far as I can tell, this change follows a number of crashes that I had while gaming (think it was Medieval 2: TW). I went back to check my BIOS settings, which do occasionally reset themselves, but I found that I was POSTing at the overclocked speed, and nothing in my BIOS had been changed.

Further adding to my confusion was the fact that Core Temp, Orthos, and Windows System Properties were now all showing 2.33 GHz (333.3x7) as my core speed. As with CPU-Z, I hadn't had any prior problems reading my overclock accurately with any of these programs. This ruled out any CPU-Z-specific bug.

My shortened memory timings are, however, displaying accurately on CPU-Z, as is my lower-than-stock vcore. This makes me wonder: are CPU-Z and the other apps that I'm using really all reading my core speed wrong? Can the BIOS ever lie about clock speed? Have I missed something obvious?

And no, this isn't a problem with EIST or C1E (both have been disabled for the past year).

Thanks in advance for your help.