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Theory: The Optimum Cooler

A Comparison of 34 Coolers for the AMD Athlon XP
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The demands placed on an optimum cooler by the user have not changed since the last test: it should be easy to fit and should, if possible, operate quietly. The cooling capacity provided should of course leave some room for a further processor upgrade.

Guidelines Of The Processor Manufacturer

The most important design parameters specified by AMD for an Athlon XP CPU cooler (Model 8) or the PXC housing are:

  • Maximum total weight: 300 grams (for coolers that are clamped to the base);
  • Maximum external measurements: 63 x 80 x 64 millimeters
  • The internal temperature in the immediate vicinity of the cooler may not exceed 42 ° Celsius in any operating status;
  • Maximum thermal output: 68.4 Watts;
  • Nominal contact weight of the holding clamp: 9 kilograms.

Physical Peripheral Conditions

In order to be able to conduct heat away from the processor as quickly as possible, the following requirements need to be met: the material out of which the heat sink is made must be highly thermally conductive, and there has to be a sufficient temperature difference between the processor die and the surrounding air. In other words, the best cooler in the world is no good to you if the temperatures inside the housing are too high. For this reason, AMD recommends a maximum internal temperature inside the housing (measured at a distance of one inch above the processor ventilator) not exceeding 40° Celsius, and a temperature difference of at least 7° from the air surrounding the housing.

The cooling capacity or heat conductivity through a cooler can be described by the following equation (considerably simplified):

Iw = G*(TD -TA ) with G=λ* (A/l)

where

Iw : heat flux
G: heat conductance
λ: thermal conductivity of the cooling material
A: area through which heat flows (contact surface between the die and cooler)
l: distance traversed by the heat flux
TD : maximum permissible die temperature according to specifications
TA : temperature in the vicinity of the ventilator

As can be deduced from the equation, given a specified temperature (TDmax =85°C and TAmax =40°C), the heat flux Iw increases the higher the thermal conductance (or the lower the thermal resistance) of the cooler, or to be more precise, the combination of cooler material, thermal interface material (TIM) and die material.

Thermal conductivity of various materials.

This explains the utilization of copper as the preferred cooling material: as the heat flux Iw corresponds to the processor's heat dissipation, cooling materials boasting higher thermal conductivity need to be used for CPUs with higher heat dissipation (=low thermal resistance).

Summary
  1. 34 Alternatives To The AMD Boxed Cooler
  2. Theory: The Optimum Cooler
  3. Thermal Interface: Pad Or Paste
  4. Measure Like The Professionals: Measuring Temperature At The Die
  5. The Coolers In Depth
  6. MF018-021
  7. AVC Co. Ltd.: 112C81 And Z6M330 Frost
  8. AVC Z6M330
  9. Coolermaster CP5-7JD1B-0L & HAC-V81-X-Dream
  10. Variable Cooling Capacity: Coolermaster HAC-V81 X-Dream
  11. Cooljag JVC652A
  12. Fanner: Spire Cu King II (5E070B1H3G) & Falcon Rock (5F271B1M3)
  13. Athlon XP Under The Rock: Falcon Rock (5F271B1M3)
  14. Global Win Technology: Cooling Towers CAK4-86, CAK4-88T & TAK58
  15. Large, Heavy And Temperature-Regulated: CAK4-88T
  16. As Quiet As A Whisper And Simple To Mount: TAK58
  17. Inconspicuous But Effective: Neng Tyi's KNO2 And KNO1
  18. Lighter, Smaller And Weaker: KN01
  19. Pentalpha APSK0168-B, APSK0181-C & APSK0181-L
  20. The Performer: APSK0181-C
  21. The Quiet One: APSK0181-L
  22. Springspread/ Neolec Vento III & Unique2800
  23. Installation Guide In The Lid: Unique2800
  24. A German Quality Product: EKL 20704101059
  25. Variable Cooler Monster For Overclockers: Swiftech MCX462-U
  26. Very Loud And Very Powerful: MCX462-U+VANTEC Tornado
  27. Easy Upgrading: Taisol CGK760098 & CGK760172
  28. Good Performance And As Quiet As A Whisper: CGK760098
  29. New-Age Volcanoes: Thermaltake Volcano 9 & Volcano 7+
  30. Manual Or Automatic: Volcano 9+
  31. Battle Of The Titans: TTC-CU5 TB & TTC-D5T(F/CU35)
  32. Good Cooling Performance But Loud: TTC-D5T
  33. Unusually Bad But Extremely Quiet: TTC-D5 TB
  34. Innovative And Very Well-Performing: Vantec Aeroflow VA4-C7040
  35. Brand-New: Molex 37256-0005
  36. Regulated Or Not: Four Tiger Electronics
  37. Heavier, Quieter And With Better Cooling Performance: Miprocool II
  38. Lighter, Smaller, But With More Cooling Power: SDC38130BC
  39. Heavy But Zippy: Dragonfly-P2B
  40. Noisy Or Quiet: From 38 To 73 DB(A)
  41. Technical Data: 34 Coolers In Comparison
  42. Conclusion: Not Much Innovation In The Cooler Market
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