So I picked up this older Dell D830. It's an old one because, even though it's a nice dual core machine, the cpu is only rated at 1.8 GHz. Still, it was really cheap and I can certainly use it.

I installed an OS, and watched while Microsoft stuffed it full of updates. While it was installing I ran CPU-Z to watch what was going on. Because of Speedstep, and because it was running on battery, the cpu speed would ping-pong between 800 MHz and 1.8 GHz. Fine - just as expected.

However, from time to time, the cpu speed would bounce up to 2 GHz. Hmmm.

Doesn't Microsoft/Dell know what the rated speed of the cpu is? Is this usual, or is there a bug in CPU-Z? Anybody else run into this? This is the only machine I've seen this happening on.

Are you seeing this happen on one of the two cores? If so, you may be seeing the effect of Intel Dynamic Acceleration (IDA) technology.

http://www.cpu-world.com/Glossary/D/...echnology.html

There is a way to enable IDA on both cores:

http://forum.notebookreview.com/wind...ore-2-duo.html

There is no way (with what I'm using) that I can see each core individually.

Reading your references (thanks!), I think it might be IDA at work. When I got the machine, the bios version was A02. The current/latest version is A17, so It was pretty far behind. One of the first things I did was flash the new bios.

I'm assuming the new bios enables IDA, and what I saw was a temporary jump from 1800 MHz to 2000 MHz, the same 200 MHz that was discussed in the second reference. So, I guess I'll just do a little reading and experimenting. Whoo-hoo! Thanks again!