Periodic CPU downclock

First of all, greetings to everyone.
I’m new to these forums. Been lurking the web to find a place to discuss the various issues.

Now to the issue, I’ve been using TMonitor to see the speed, but noticed something rather weird: each ~2 seconds, it reports that CPU freq drops to minimum for a very short period of time. I’m writing off some app stuttering to this (though not that bad, but sometimes noticeable and periodic).

Screenshot in attachment.

Operating System: Windows 7 Professional 64-bit (6.1, Build 7600) (7600.win7_gdr.100226-1909)
System Model: Dell Precision M6300
BIOS: Phoenix ROM BIOS PLUS Version 1.10 A13
Processor: Intel(R) Core™2 Extreme CPU X9000 @ 2.80GHz (2 CPUs), ~2.8GHz
Motherboard: Intel PM965
Video: nVidia Quadro FX3600M
Memory: 4096MB RAM
Page File: 2948MB used, 7287MB available

Why can it be? And what can I do?

Thanks in advance.