P4 CPU upgrade lets fan rev up!

I just sucessfully upgraded my stock 3 GHz system with a 3.8 GHz (2Mb cache/64-bit). The machine started right up, didn't even halt for the BIOS to show the new processor data. And in the Windows Performance rating the cpu is now as fast as the memory (4.5) and not the only bottleneck anymore.

BUT with that came an annoying issue: the big main fan that also cools the heat sink runs at a much higher rpm level now. I used arctic silver thermal paste between cpu and heat sink and I am sure I did that right. The old cpu had some crappy old paste on it that forsure didn't do a better job.

Could it be that the new cpu is running at a higher temperature level triggering the fan to rev higher? Or could anything be wrong with the cpu? I got it used on ebay from a trustworthy seller, it was used but tested and has a 1 year warranty.

The only thing I could think of was resetting the BIOS by removing the cmos battery in hopes that this would kinda recalibrate the fan control, but to no avail. That said I don't see any chance to modify the fan rpm level through the BIOS, it has no such settings whatsoever.

Oh and should you propose next thing to do for me is getting a program to measure the actual cpu temp: so far there is none out there that is able to handle P4 cpu's due to their missing digital thermal sensor. I had just gone through that recently even being in contact with some of the developers. They keep working on it but would not want to raise my hopes.

Any other ideas....? I would be bummed if I had to go back to the 3GHz just because of that!

Speedfan has a Dell support function but that doesn't work on my machine. And as far as I know, this one was specifically developed for Dell laptops.

Yeah I guess the 3.8 runs at generally higher temps than the 3.0. But I'm not saying with the stock cooler the cpu's life is at risk. The fan is just working harder maintaining the required temp, resulting in a noise level that I wasn't used to. Once I know for sure the 3.8 normally runs at a higher temp I may start looking into quieter fans.

Upgraded with a regular 3.8 (670 model) cpu. I followed exactly the "grain of rice" size application method. But when I checked the paste distribution/contact pattern today, it does not look too good. Trying to remember now what it looked like when I removed the 3.0 I believe that was better. But would it be the cpu? I don't think so.
Then I cleaned everything and applied new paste. Checked contact pattern and again it was poor. The heat sink sits on the cpu maybe on half of it's total surface, and unfortunately that affects the important center area (around the core) as well. Whether or not that is the reason for the high rpm remains to be determined, but it does no good for sure.
The heat sink/fan assembly is stock, but it's mounting mechanism to the cpu is somewhat wobbly. Since it is Dell specific I am not sure if I could get something better instead though.

No temp info whatsoever in the bios.

In another forum I read that I can reduce cpu load by adding RAM, is that true? And why would that be?

And again the question, could a defective cpu technically result in high operating temps?

Wow... just put the 3 GHz back in and not only is the fan running at a constant low, almost inaudible speed, but the machine appears to run smoother and faster than with the 3.8! Right now it feels as if it was running with applied handbrake before.

Is it even possible that the 3.8 had reduced performance because of it's apparent high temp?

Or could the perceived drop in performance of a 32-bit OS be related to the 64-bit cpu? I could have as well went with a 3.8 32-bit processor but I was thinking, once I would reinstall Windows 7 at some point I would have the option to go with the 64-bit version.

I'm kinda tired of all that cpu swapping right now, but when I've recovered I'm gonna check again the contact pattern I'm having with the 3.0 right now. I doubt this is the (only) reason for the rpm issue, though.

Good thoughts Fumz... I see, wobbly wasn't probably the precisest way to describe it. Once the heat sink is fastened through the shroud to the case it has a force fit to the cpu. This assembly has a special design with the heat sink moveable (wobbly) in the shroud, so that it centers over the cpu as the screws are tightened. I just think this centering design isn't the smartest, and the large shroud/heat sink assembly tolerances affect the press fit to the cpu directly. This situation, along with a presumable so-so evenness of the heat sink face (compared to the cpu) appears to result in the poor contact pattern.
I redid this assembly with the 3.8 at least 3 times, but the contact pattern was dissatisfactory every time. I guess it won't be a lot different with the 3.0 which I will check some time later this week. So it turns out this system isn't able to benefit from the better performance of the 3.8 for lack of ability to regulate the 3.8's thermal behaviour. I keep looking for a better aftermarket heat sink solution fitting my computer before I reconsider a hotter cpu.