>Hi,
>
>>>
>It is a laptop, the CPU's can run at variuos rates, depending on power saving etc.
>>>
>
>So you're say the first figure is the CPU 'design' speed and the second reflects the speed that the CPU is currently runnning at?
>
>Although the form on the URL pertains to a laptop I only used it as an example. The machine I'm really concerned with is a desktop PC (with power management disabled). The relevant section reads:
>

>Intel(R)
>Pentium(r) 4 CPU 2.80GHz
>2.10GHz
>

>so the implication is that this is a 2.8GHz processor running at 2.10Ghz. Any suggestions as to why (or how to find out why) it's running at this reduced speed ?

The link on your first message is for what Dell seems to be calling a "Pentium 4 - M" processor. I believe this example is actually a Pentium-M processor, which is a completely different architecture from the P4. Like various AMD processors, the PM processor is much more efficient than a P4; a PM running at 1.2GHz has roughly the same performance as a P4 at 2GHz. The PM processor is also energy-efficient and is widely used in laptop computers.

Having said all that, PM processors are still very uncommon in desktop PCs. The whole industry is currently very unsettled in what it calls "speed ratings" (in your case the 2.8GHz figure); it might be that even Intel differentiates actual processor clock speed from "speed ratings" amongst its own processor (and processor core) families.