Asetek Vapochill Micro CPU heatsink/fan

Cooling
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TESTING


On the test bench...

Test Platform

  • Intel P4-2.8A The Thermal Design Power of this P4-2.8 (533 MHz bus) is 68.4 or 69.7W depending on the version. As the CPU is a demo model without normal markings, it's not clear which version it is, so we'll round the number off to ~69W. The Maximum Power, as calculated by CPUHeat & CPUMSR, is 79W.
  • AOpen AX4GE Max motherboard - Intel 845GE Chipset; built-in VGA. The on-die CPU thermal diode monitoring system reads 2°C too high, so all readings are compensated up by this amount.
  • OCZ DDRAM PC-3200, 512 MB
  • Seagate Barracuda IV 40G 1-platter drive (in Smart Drive)
  • Seasonic Super Tornado 300 (Rev. A1)
  • Arctic Silver Ceramique Thermal Compound
  • Nexus Real Silent 92mm fan
  • Two-level plywood platform with foam damping feet. Motherboard on top; most other components below. Eases heatsink changes and setup.

Measurement & Analysis Tools

  • CPUBurn processor stress software
  • SpeedFan version 4.25 software to show CPU temperature
  • A custom-built fan controller that allows us to dial in exactly what voltage is powering the fan
  • B&K model 1613 sound level meter
  • Electronic Anemometer, to measure airflow

Noise and airflow measurements were made with the fan powered from the fan controller while the rest of the system was off to ensure that system noise did not skew the measurements.

Airflow measurements were made while the fans were mounted on the Vapochill Micro heatsink, and are lower than they would be if they were measured in free air.

Load testing was accomplished using CPUBurn to stress the processor, and the graph function in SpeedFan was used to make sure that the load temperature was stable for at least ten minutes.

The ambient conditions during testing were 16 dBA and 21°C.

THE FANS

Before any thermal testing was done, the three supplied fans were compared to see which sounded the best. We expected that the "Ultra Low Noise" fan would take this crown, but we were surprised to find otherwise. Our 92mm reference fan, a Nexus, was also thrown into the mix.

Asetek Vapochill Micro: Fan Specifications

Fan

Ultra Low Noise
Extreme Performance
High End

Brand

Panaflo
Not Listed
Not Listed

Bearing Type

Hydro Wave
Sleeve
Sleeve

Input Current

0.2A
0.5A
0.55A*
Noise
28 dB(A)
39 dB(A)
35 dB(A)

Rated Speed

2350 RPM
3800 RPM
3800 RPM

Air Flow

17.657 CFM†
73.656 CFM
67.0 CFM

Life Expectancy

50,000 hours
31,000 hours
31,000 hours

*This rating is contradicted by what is listed on our sample fan. Our fan was marked 0.39A.
† 17 CFM seems too low for 2350 RPM; if it is a transcription error, it's not ours but Asetek's.

On paper, the "Ultra Low Noise" fan is clearly the quietest. It's rated for less than half the current of the other fans, spins at about half the speed, and has a greater life expectancy to boot. It's even made by Panaflo, a brand well known for making quiet fans, and has the famous Hydro Wave bearing. It also uses a traditional three-pin fan header, unlike the other fans which have an extra pin for PWM-based speed control. The Ultra Low Noise model ships with a fan controller, so the loss of motherboard-based speed control isn't all that important.

The others are high speed fans, which usually means they're unacceptably noisy. The manufacturers for these two fans are not listed — perhaps the brand isn't such a selling point outside of the quiet market.

At full speed, the "Ultra Low Noise" fan was indeed the quietest of the stock fans. But, the results at lower speeds told a different story: Below 9V it was the loudest. The High End fan was much quieter, especially below 8V.

Undervolting is a common silencing technique, since almost all fans are too loud at stock speed. For this reason, we judge fans based on how well they perform even when they're not powered with a full 12V. When judged in this way, Asetek's High End fan has the most potential in a low noise system: It is capable of being quieter than either of the other two stock fans.

MEASURED FAN DATA

Asetek Extreme Performance Fan

Asetek High End Fan

Fan Voltage

Airflow (CFM)
SPL (dBA@1m)

Fan Voltage

Airflow (CFM)
SPL (dBA@1m)

5V

9
20

5V

N/A
<16

7V

14
22

7V

5
18

9V

37
41

9V

24
29

12V

58
50

12V

49
45

Asetek Ultra Low Noise Fan

Nexus Reference Fan

Fan Voltage

Airflow (CFM)
SPL (dBA@1m)

Fan Voltage

Airflow (CFM)
SPL (dBA@1m)

5V

9
22

5V

5
<16

7V

16
27

7V

10
17

9V

21
31

9V

13
18

12V

28
36

12V

18
22
Airflow measurements were made with the fan mounted on the Vapochill Micro heatsink.

But, judging fans solely on the basis of noise doesn't really make sense: What matters is the airflow a fan can produce at a given amount of noise. So, before we decided which fan we would use for thermal testing, we ran one more test, this time holding noise constant and directly comparing the amount of airflow that each fan was capable of. The target noise level was 22 dBA@1m.

Fans on Vapochill Micro: Noise vs. Airflow
(All fans were calibrated to 22 dBA@1m)

Fan

Voltage (V)
Airflow (CFM)

Nexus Reference

12
18

High End

8
15

Extreme Performance

7
14

Ultra Low Noise

5
9

Once again, the "High End" fan proved to be the best performer of the stock fans, beating out the "Extreme Performance" fan by a hair. But, none of the stock fans could compare to the performance of the reference fan, which pushed 20% more air at this noise level than any of the other fans. The "Ultra Low Noise" fan is the clear loser in this comparison, as it generated only half the airflow of the reference fan.

Based on the testing presented above, the "High End" fan seems to be best suited for use in a low noise system, so we decided to use it for our thermal testing.

On to the thermal results...



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