Specifications and Pricing

The following table lists the specs and recommended prices of the tested coolers:

Testbed and Methods

The coolers were tested on an open testbed and in a system case with the following configuration:

• Mainboard: ASUS P5K Deluxe/WiFi-AP (Intel P35 chipset, LGA775, BIOS 0501)
• Processor: Intel Core 2 Duo E6400 (2133MHz, 1.325V, 266x4MHz FSB, 2048KB L2 cache, SL9S9 Malay, Conroe B2)
• Thermal interface: Arctic Silver 5
• Graphics card: Sysconn GeForce 7900 GS GDDR3 (256MB, 256-bit, @575/1710MHz)
• Graphics card cooler: Arctic Cooling Accelero S1 in passive mode
• Memory: 2 x 1024MB Corsair Dominator TWIN2X2048-9136C5D DDR2 SDRAM (SPD: 1142MHz, 5-5-5-18, 2.1V)
• Disk subsystem: Hitachi HDT725032VLA360 (SATA-II, 320GB storage capacity, 7200rpm, 16MB cache, NCQ)
• Optical drive: Samsung SH-S183L DVD-burner (SATA-II)
• System case: ASUS ASCOT 6AR2-B Black&Silver (with two 120mm 980rpm system fans Sharkoon Luminous Blue LED for intake and exhaust and a 1200mm 750mm Scythe fan on a side panel)
• Power supply: Enermax Galaxy EGA1000EWL 1000W (a 135mm 850rpm fan for intake and a 80mm 1650rpm fan for exhaust)

I’ll explain in the Results section why I had to use a dual-core CPU instead of the traditional quad-core model.

All tests are performed in Windows XP Professional Edition Service Pack 2. SpeedFan 4.32 is used to monitor the temperature of the CPU, reading it from the CPU sensor. The CPU is heated up by means of OverClock Checking Tool version 1.1.0 in a 24-minute test during which the system remains idle in the first and last 4 minutes.

The mainboard’s automatic fan speed management is disabled for the time of the tests. The thermal throttling of the Intel Core 2 Duo processor is controlled with RightMark CPU Clock Utility version 2.25. Our CPU begins to skip clock cycles on reaching a temperature of 82°C and higher.

I perform at least two cycles of tests and wait for 20-25 minutes for the temperature to stabilize during each test cycle. The maximum temperature of the hottest CPU core in the two test cycles is considered as the final result (if the difference is not bigger than 1°C – otherwise the test is performed once again). Despite the stabilization period, the result of the second cycle is usually 0.5-1°C higher.

The ambient temperature was monitored by means of an electric thermometer and remained at 28.5°C during the tests. The fan rotation speed is shown in the diagram as reported by monitoring tools.

I took two opponents to the tested coolers: Zalman CNPS9700 LED and Thermalright Ultra-120 Extreme. The Zalman CNPS8700 LED is about $20 cheaper than the CNPS9700 LED and is positioned differently on the market. So I guess it’s interesting to know how weaker the more compact and cheaper cooler is in comparison with Zalman’s top model. The Thermalright Ultra-120 Extreme is currently one of the best air coolers if not the very best one. So it makes a good point of reference. I tested the cooler from Thermalright with two very quiet 1100rpm Scythe Minebea fans installed for intake and exhaust.