How hot do Pentium 4 Processors run?

[jamesbond007]

Hey guys. I'm just curious as to how hot the Pentium 4 processors run? I'm not willing to dish out the serious dough that they cost right now to find out. I'm also waiting for the Northwood core, as well. (I think that's it anyways.) I know Pentium 3 cores run pretty cool, compared to current Athlon specs, and was just wondering how the Penitum 4 CPUs compare to the above.

On another note, are any of you guys even considering buying a Pentium 4 Processor, even with the projected price drop???

Thanks.

 

[thermite88]

jamesbond007 asked:

<< how hot the Pentium 4 processors run? >>

The answer is found in the Intel P4 Datasheet.

The power of the P4 depends on the CPU speed. The Intel P4 will shut down at 103C, and start throttle back at the following conditions of Maximum CPU case (TCase) temperatures:

Processor and......Thermal Design.....Minimum.....Maximum
Core Frequency.....Power (W)2.........TCase(°C)...TCase(°C)....Notes

1.30GHz....................48.9........................5......................69.............1
1.40GHz....................51.8........................5.....................70.............1
1.50GHz....................54.7........................5.....................72.............1

For example, the 1.5 GHz P4 will start throttle back when the CPU case temperature reaches 72 degrees C. When will it reach 72C depends on two factors, the ambient (computer case) temperature and the heatsink used. If you use a very good heat sink, such as one of the Alpha, which has an efficiency (case to ambient thermal resistanec) of 0.25 C/W, the CPU temperature (Tcase) will be 13.7 degrees C above the ambient (computer case) temperature.

TCase (CPU) = Tambient + (0.25C/W x 54.7 watts) = Tambient + 13.7C

In other word, the P4 will start throttle back when the ambient temperature reaches 58.3 degree C (137F). I would say that it is highly unlikely to happen in normal condition. But it can happen if your case fan malfunction or the vent get blocked by dust. In that case, you will be glad that the P4 has the thermal protection.

Let me assume a worst case scenario. You live in a tropical country and does not have air conditioning in your room. It is a 105 degrees F hot day (40C) and the computer case is 8 deg C above the room temperature. Tambient = 48 deg C.

The CPU temperature will be

TCase (CPU) = 48 + (0.25 x 54.7) = 61.7 deg C.

It will be closer to the throttle back TCase (10.3C below), but still a reasonably safe margin. It is more than 40C below the P4 shutdown temperature.

All the above calculation assume that you use a good quality heatsink and install it properly. The good news is that even if you make a mistake installing the HSF, you will get reduced performance until you correct the problem. The chance of getting a burnt CPU is much less than using AMD CPU's.

 

[jamesbond007]

Wow! Thanks for the info. It only makes me wonder why AMD doesn't implement this kind of protection in their CPUs. Maybe we will see something similar to this in the upcoming Palomino chips. It's bad when you aren't using protection.

 

[thermite88]

AMD already anounced that the Palomino will have thermal protection implemented. No details yet.

 

[jamesbond007]

Cool beans man.