Testbed and Methods

Swiftech H₂0-220 Apex Ultra+ was tested inside a system case with the side panel removed. Our testbed was configured as follows during this test session:

• Mainboard: ASUSTek P5K Deluxe/WiFi-AP (Intel P35), LGA 775, BIOS 0812
• CPU: Intel Core 2 Extreme QX9650 (3.0GHz, 1.25V, 2x6MB L2 cache, 4x333MHz FSB, Yorkfield, C0)
• Thermal interface: Arctic Silver 5 (for all coolers)
• Graphics card: HIS Radeon HD 4850 GDDR3 512MB / 256bit, 625/2000MHz
• Graphics card cooler: Arctic Cooling Accelero S1 + Turbo Module
• Memory:
  • 2 x 1024MB DDR2 Corsair Dominator TWIN2X2048-9136C5D (1142MHz / 5-5-5-18 / 2.1V);
  • 2 x 1024MB DDR2 CSX DIABLO CSXO-XAC-1200-2GB-KIT (1200MHz / 5-5-5-16 / 2.4V).
• Disk subsystem: Western Digital VelociRaptor (SATA-II, 300GB storage capacity, 10000RPM, 16MB cache, NCQ)
• HDD silencer and cooler: Scythe Quiet Drive 3.5”
• Optical drive: Samsung SH-S183L SATA-II DVD RAM & DVD±R/RW & CD±RW
• System case: ASUS ASCOT 6AR2-B Black&Silver (ATX) with 120mm ~900RPM Scythe Slip Stream 120 fans for air intake and exhaust (the fans are installed on silicon spindles)
• 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 Vista Ultimate Edition x86 SP1. SpeedFan 4.34 was used to monitor the temperature of the CPU and mainboard, reading it directly from the CPU core sensor and to monitor the rotation speed of the cooler fans:

The mainboard’s automatic fan speed management feature was disabled for the time of the tests in the mainboard BIOS as well as the processor power-saving technologies. 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 30-minute test with maximum CPU utilization, during which the system remained idle in the first 1 and last 4 minutes of the test:

In response to numerous readers’ requests, we have also created additional load with IntelBurnTest v1.6 (by AgentGOD) that uses Linpack 32-bit stress-test algorithm. It turned out that we needed only 10 runs of Linpack program (load mode – 2) to have the CPU reach its maximum temperature with the liquid-cooling system.  Air coolers required even fewer runs than that. Nevertheless, we increased the number of runs up to 15:

The full screenshot from Linpack test looks as follows:

I performed at least two cycles of tests for each test application 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).

During the graphics card thermal test we used the Firefly Forest benchmark from the synthetic 3DMark 2006 graphics suite. We ran this benchmark 10 times in 1920x1200 resolution with enabled 4x full-screen antialiasing and 16x anisotropic filtering. The GPU temperature and frequencies were monitored using RivaTuner v2.10 (by Unwinder).

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 temperature was pretty low: 19~19.5°C. It is used as a starting 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.

We will be comparing Swiftech H₂0-220 Apex Ultra+ against two extreme air-coolers. For the CPU we used Thermalright IFX-14 with two Thermaltake TurboFan fans (140 x 140 x 25mm, ~1000RPM rotation speed). And for the graphics card we used Arctic Cooling Accelero S1 with a Turbo-Module. The side panel of the system case was removed during the entire test session:

The total cost of these two cooling systems was around $130. As I have already said before, we didn’t install the water block onto the mainboard chipset, so in both cases a reference heatsink was involved.