Why does my 2.8GHz Mobile P4 seem to be running at 1.6GHz?

My laptop is an HP Pavilion zx5000. It is supposed to have a Mobile Pentium 4 2.80GHz processor. But when I look in the System control panel, the bottom section of information says says:

I thought this was probably just a fluke, until a program that I was installing this morning also reported the speed of my processor as 1.60Ghz. What’s the deal with that? It’s running Windows XP Professional SP1a, and it doesn’t have any speed-modifying software installed like some of my other laptops do (such as my Sony Vaio Picturebook, which actively modifies the speed of the processor depending on how much power is available). And the BIOS doesn’t seem to have any options for changing processor speed. So … does anybody know what the deal is?

This is why it’s called mobile. The processor runs at the lowest possible speed in order to conserve energy. If you run a resource-intensive application it should speed up to full throttle. But for simple tasks like e-mail, web, and word processing it doesn’t need to, most of the time. AFAIK it does this internally - but how exactly, I have no idea.

What he said ^^^. It’s completely normal.

Yes, my old IBM T23 with a Pentium mobile 1.13 GHz chip sometimes runs as low as 533MHz when doing tasks like reading e-mails, using Word or anything that does not require the full speed of the processor. Saves on battery life.

Thanks HanoNymus and Rex. I was about to ask why it always shows up as 1.60GHz, but I figured maybe I just always went into the System control panel while the computer was idling. So I dropped to a command prompt and did a DIR /S and went back in, and sure enough, now it reports 2.80GHz. That’s a load off my mind!

… And thanks to Amp too. I wasn’t excluding you, I just composed that reply before you posted. :wink:

The reason I found this whole situation odd is that it was running at such a low speed while plugged in. I thought the power-saving features would only be enabled while running on battery power, like with my Picturebook.