New Stock Intel Prescott P4 Cooler

Cooling
Viewing page 2 of 3 pages. Previous 1 2 3 Next

TEST RESULTS

The unit was tested on a P4-2.8 (533 MHz bus) system open-bench testing rig. Intel rates this CPU with a Thermal Design Power (TDP) of 69W. A more realistic calculation of Maximum Power (MP) under heavy CPU load such as CPUBurn pegs it at 79W. °C/W is calculated using both numbers. The ambient temperature was 20°C. CPUBurn stress-testing software was used to achieve the load temperatures. All measurements were performed after temperatures stabilized, usually within 15~20 minutes.

Intel P4-2.8 Prescott HSF
Fan voltage / RPM
12V / 2500
7V / 1200
5V / 690
Load temp
48°C
63°C
stopped at 78°C
Rise from ambient
28°C
43°C
-
°C/W (TDP)
0.41
0.62
-
°C/W (MP)
0.35
0.54
-
Measured Noise (dBA@1m)
37
33
28
Comment
Muted whine, turbulence noise and clicking/buzzing noise.
Noisy with clucking sound that reminds one of a diesel-engine
Not noisy, but clucking noise seems even more prominent
Ambient temperature during test: 20°C

Performance is not exactly scintillating. Even with the fan set at the full 12V, the temperature rise is a pretty high 28°C. The 43°C temp rise at 7V is probably unacceptable inside a normal case where the ambient temp is likely to be at least 30°C. At 5V, this HSF is completely unusable.

The noise is high at 12V and still not acceptable at 7V. At all reduced speeds, the fan exhibits a pronounced buzziness that is reminiscent of a diesel engine.

The CPU used for this test is an older P4-2.8/533. Had it been a 2.8 Prescott, the wattage figures would be 89W for TDP and 100W for MP. That would mean considerably higher temps. My calculations based on the °C/W (MP) obtained above suggest the following, assuming the same 20°C ambient temp:

Calculated Temperatures with P4-2.8 Prescott
Fan voltage / RPM
12V / 2500
7V / 1200
Load temp
55°C
74°C
Rise from ambient
35°C
54°C
°C/W (MP)
0.35
0.54

These results are barely acceptable at the 12V fan setting. Inside a case, you'd probably see CPU temps in the mid to high 60s°C. At 7V, it's not safe to use at all.

How does this compare with the previous full copper base Intel HSF? Here a summary of the data from that review.

Retail Intel P4 3.0C HSF
Fan voltage / RPM
12V / 3080
7V / 2400
5V /1820
Load temp
44°C
49°C
52°C
Rise from ambient
22°C
27°C
30°C
°C/W (MP)*
0.28
0.35
0.38
Measured Noise (dBA@1m)
39
34
32
Comment
Loud whine, lots of air noise and clicking.
Low pitched whine, noticeable clicking/rattling.
Still not quiet, ticking noise and electric "hum"

* Based on 66W for TDP and 78W for MP.

Here is a comparison between the two HSF, based on their °C/W (MP) calculated for a 100W (MP) Prescott P4-2.8 and a case ambient temp of 32°C.
Old HSF vs New HSF: Calculated In-Case CPU Temps with P4-2.8 Prescott
Fan voltage / RPM
Copper Base
12V / 3080
7V / 2400
5V /1820
New Prescott
12V / 2500
7V / 1200
5V / 660
Load temp
Copper Base
60°C
67°C
70°C
New Prescott
67°C
82°C
N/A
Rise from ambient
Copper Base
28°C
35°C
38°C
New Prescott
35°C
54°C
N/A
°C/W (MP)*
Copper Base
0.28
0.35
0.38
New Prescott
0.35
0.54
N/A
Noise (dBA@1m)
Copper Base
39
34
32
New Prescott
37
33
28
The new HSF is a considerably worse performer. It seems pretty clear that it is not safe to reduce the fan speed of this new HSF when used with a Prescott P4-2.8 in a typical case. The older copper base "high end" heatsink is better, though louder. This new HSF appears to be an attempt to reduce noise, but the price is merely adequate performance under near-ideal conditions.


Previous 1 2 3 Next

Cooling - Article Index
Help support this site, buy from one of our affiliate retailers!
Search: