Bought a P4 2.8 chip but it's running at 2.1

Instead of buying a new computer I decided to give this old P4 1.8 Compaq computer, YES A COMPAQ COMPUTER, some more life. I bought a P4 2.8 from newegg.com (would had bought a 3.0 but mobo doesn't support HT, plus they just sold out) and this was my first time installing/replacing a CPU so was VERY cautious. I successfully replace it and put everything back together. I start up the computer, log in into my XP account and checked the properties. It display the chip as P4 2.8 but it's running only at 2.1. So I restart the computer and go into the BIOS and sure enough it detects as a P4 2.1 chip. I went to HP web site and see if they had any BIOS update and they did. I install/flash it and restarts the computer. Now before Windows loads, it says something about wrong microporcessor and updating BIOS (it display the info TOO quick for me to read it!) but then loads normally. Again I log in and check properties and still show that it's running at 2.1. I restart and go into BIOS again and this time it detects the chip as P4 2.8. Now I'm clueless on how to make it run at 2.8.

Now I did search around and in various sites says you can change the info of your CPU in the BIOS but when there's nowhere to be found in the BIOS. Others says it might be due to the CPU is on low power comsumption but this isn't a laptop. Then I came across about temperatures but the CPU isn't running very hot or overheating.

Perhaps the properties and even the Intel Processor ID ulitity is displaying it wrong? When I watch a HD clip/movie encoding in x264 on my 1.8 chip there was lots of scene where it will stutter. When playing the same clip/movie on the 2.8 chip and will only stutter where a scene encoded in higher bitrate.

Sorry for the long post but any help will be appreciated. Thanks in advance.

Jam it back in, in the dark.

Hmm... perhaps so. Where else would I look for settings on the chip?

At first I was hesitated to buy a chip to upgrade but I read that people was sucessfully doing so, including running at intended speed, on name brand computers like Dell, eMachine and even older model of Compaq computer than the one I have. If I can read that warning/notice before Windows load maybe it can help me on the problem. I might have to "take a picture" to see it.

If I have to come to this (most likey I will) should I return the chip to newegg.com to exchange for a lower chip like a 2.4 (perhaps it's more "compatible" and will run at full speed) or just return it and save up to buy a new computer?

There's nowhere I can't reach.

I did say that I was hesitated into buying the chip because I did have a feeling that upgrading a CPU on a name brand computers wouldn't work but when I did my research and see that others were able to, even on older model (including a Dell!). So I decided to give it a try.

In any case I will RMA it. Thanks anyway.

This thing is sticky, and I don't like it. I don't appreciate it.