Testbed and Methods

The CoolIT Freezone and its opponent were tested in a system case with the following configuration:

• Mainboard: ASUS P5B Deluxe/WiFi-AP (Intel P965 chipset, LGA775, BIOS 1215)
• Chipset cooler: Thermaltake Extreme Spirit II (~2500rpm)
• Processor: Intel Core 2 Quad Q6600 (2400MHz, 1.2875V, 266x4MHz FSB, 2x4096KB L2 cache, Kentsfield B3)
• Thermal interface: Arctic Silver 5
• Graphics card: Sysconn GeForce 8600 GTS (256MB, 128-bit, 675/2016MHz)
• Graphics card cooler: Arctic Cooling Accelero S2 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 system fans Sharkoon Luminous Blue LED (980rpm) for intake and exhaust
• Power supply: Enermax Galaxy EGA1000EWL 1000W (a 135mm 850rpm fan for intake and a 80mm 1650rpm fan for exhaust)

The CPU with a slightly polished-off heat-spreader was overclocked to its maximum frequency on the weakest of the tested coolers. You’ll learn shortly which cooler it was. The resulting frequency was 3294MHz at a core voltage of 1.4875V.

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 60-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 25-30 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 26°C during the tests (marked with a vertical red line in the diagrams). The fan rotation speeds are shown in the diagrams as reported by monitoring tools.

Fortunately, I don’t have an air cooler with a recommended price of about $400. I have a Zalman Reserator 2, yet it costs considerably less, below $300. And it is much harder to assemble it than to install a good air cooler. So, I took an Enzotech Ultra-X cooler in quiet mode (1300rpm) as an opponent to the CoolIT Freezone.