D820 CPU throttling

First off, the search function hasn't been working for me, so my apologies if this has already been answered in another thread.

At any rate, I have a D820 with a T5600 CPU. The max clock on the CPU is 1.83 Ghz, but HWInfo never shows the CPU running any faster than 1.46 Ghz. I've never seen it report the current FSB speed as being any higher than 133 Mhz, even though it says the max FSB is 166.7 Mhz. Any idea why my CPU (apparently) isn't running at full speed?

Thanks!

 

Are you sure you are taking these readings under full CPU load? (ie under Prime95, etc)

 

Good call; I hadn't tried that yet.

I just ran CPU Burn-in, but my CPU still maxes at 1.4Ghz with the FSB stuck at 133 Mhz.

 

Can you try prime95? Also, are you on the latest BIOS?

 

I updated to the latest BIOS available from Dell and ran several torture tests with Prime95, but I still haven't been able to get it above 1.4 Ghz.