Testbed and Methods

The Thermalright coolers we have just discussed and their competitors were tested in two modes: in an open testbed when the mainboard sits horizontally on the desk and the cooler is installed vertically, and in a closed testbed with the mainboard in vertical position.

Our testbed was identical for all coolers and featured the following configuration:

• Mainboard: ASUSTek P5K Deluxe/WiFi-AP (Intel P35), LGA 775, BIOS 0812
• Processor: Intel Core 2 Extreme QX9650 (3.0GHz, 1.25V, 2x6MB L2 cache, 4x333MHz FSB, Yorkfield, C0)
• Thermal interface: Arctic Silver 5
• Graphics card: Sysconn GeForce 8800 GTS GDDR3 512MB / 256bit, 650/1940MHz
• Memory:
  • 2 x 1024MB DDR2 Corsair Dominator TWIN2X2048-9136C5D (1142MHz / 5-5-5-18 / 2.1V);
  • 2 x 1024MB DDR2 CSXO-XAC-1200-2GB-KIT DIABLO (1200MHz / 5-5-5-16 / 2.4V).
• Disk subsystem: Samsung HD501LJ (SATA-II, 500GB storage capacity, 7200rpm, 16MB cache, NCQ)
• Optical drive: Samsung SH-S183L SATA-II DVD RAM & DVD±R/RW & CD±RW
• System case: System case: ASUS ASCOT 6AR2-B Black&Silver (ATX) with 120mm ~960RPM Scythe Slip Stream fans for air intake and exhaust (the fans are installed on silicon spindles), and the same 120mm ~800RPM fan on the side panel
• Control and monitoring panel: Zalman ZM-MFC2
• Power supply: Enermax Galaxy EGA1000EWL 1000W (a default 135mm fan for intake; and 80mm fan for air exhaust)

All tests were performed under Windows XP Professional Edition SP2. SpeedFan 4.34 Beta 44 was used to monitor the temperature of the CPU, reading it directly from the CPU core sensor:

The mainboard’s automatic fan speed management feature was disabled for the time of the tests in the mainboard BIOS. The CPU thermal throttling was controlled with the RightMark CPU Clock Utility version 2.35.0:

The CPU was heated up with OCCT (OverClock Checking Tool) version 2.0.0a in a 23-minute test with maximum CPU utilization, during which the system remained idle in the first 1 and last 4 minutes of the test:

I performed at least two cycles of tests and waited for approximately 20 minutes for the temperature inside the system case to stabilize during each test cycle. The stabilization period in an open testbed took about half the time. Despite the stabilization period, the result of the second test cycle was usually 0.5-1°C higher. The maximum temperature of the hottest CPU core of the four in the two test cycles was considered the final result (if the difference was no bigger than 1°C – otherwise the test was performed at least once again).

The ambient temperature was checked next to the system case with an electronic thermometer that allows monitoring the temperature changes over the past 6 hours. During our test session room temperatures varied between 24.0 ~ 24.5°C. It is used as a staring point on the temperature diagrams. Note that the fan rotation speeds as shown in the diagrams are the average readings reported by SpeedFan, and not the official claimed fan specifications.

The noise level of each cooler was measured according to our traditional method described in the previous articles with the help of an electronic noise meter – CENTER-321. The subjectively comfortable noise level was considered 34.5dBA and is marked with a dotted blue line in the diagram. The ambient noise from the system case without the CPU cooler didn’t exceed 32.5dBA when measured at 1m distance.

As you may have already guessed, our today’s heroes will be competing not only against one another. We have also added the results for Thermalright Ultra-120 eXtreme and Thermalright SI-128 (both with their original retentions) from the previous test sessions, which we have been using as performance reference for quite some time (for tower and top-coolers, respectively). I would like to remind you that both these coolers have even base surface without any dents and didn’t require any additional polishing. All Thermalright coolers were equipped with one or two Scythe SlipStream 120 fans working at ~860RPM and ~2000RPM.

And in order to spice up the race with a non-Thermalright participant, we added the results for a very successful ZEROtherm Nirvana NV120 Premium cooler:

We tested this cooler in two modes: with the fan rotating at ~1280RPM with moderate noise and at maximum fan rotation speed of ~2780RPM and very high level of noise.