Testbed and Methods

The Zalman Reserator XT system and its opponent were tested in a closed system case with the following configuration:

• Mainboard: ASUS P5K Deluxe/WiFi-AP (Intel P35 chipset, LGA775, BIOS 0501)
• 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 7900 GS GDDR3 (256MB, 256-bit bus, 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: Samsung HD501LJ (SATA-II, 500GB 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 120mm 940rpm GlacialTech fan on a side panel
• Power supply: Enermax Galaxy EGA1000EWL 1000W (a 135mm 850rpm fan for intake and a 80mm 1650rpm fan for exhaust)

The quad-core CPU was overclocked to the maximum stable frequency it had with the air cooler. That was 3483MHz. The core voltage was set at 1.6625V in the mainboard’s BIOS.

CPU-Z, SpeedFan and Everest reported a core voltage of 1.59V at that. The memory voltage was increased to 2.1V. The other mainboard voltages were left at their defaults.

All tests are performed in Windows XP Professional Edition Service Pack 2. SpeedFan 4.33 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 1.1.1 in a 24-minute test during which the system remains idle in the first and last 4 minutes for the temperature to stabilize.

The mainboard’s automatic fan speed management (Q-Fan technology) is disabled for the time of the tests. The thermal throttling of the Intel Core 2 Quad processor is controlled with RightMark CPU Clock Utility version 2.30. 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 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 with the air cooler. The results of both tests were identical with the liquid cooling system.

The ambient temperature was monitored by means of an electric thermometer and remained at 23.5-24°C during the tests (marked with a red line in the diagrams). The fan rotation speeds are shown in the diagrams as reported by SpeedFan.

The noise level of each cooler was measured according to our traditional method. The subjectively comfortable level of 36dBA is marked with a dash line in the diagram; the ambient noise from the system case, without the CPU cooler, was about 34dBA when measured from a distance of 1 meter.

The Zalman Reserator 2 was tested in our labs in comparison with the Enzotech Ultra-X cooler. And now, the new Reserator is going to be compared with a more formidable opponent. It is the Thermalright Ultra-120 eXtreme with two high-performance Scythe Minebea fans (4710KL-04W-B29) for intake and exhaust. Of course, the price of the air cooler is going to be only one fourth that of the recommended price of the Reserator XT even with the two rather expensive fans. However, none of liquid cooling systems we have tested so far could match the performance of the competing air cooler. Let’s see what we have this time around.