Testing Methodology

Testing was conducted in a loosely scientific manner. Ambient room temperatures levels were held to within one degree of fluctuation measured at static point beside the test equipment with a calibrated digital thermometer. All coolers had their original manufacturer-supplied fan removed and replaced with our common test fan listed in the support equipment section below. Each product then received the same amount of Thermal Interface Material (specified below), which amounted to roughly a BB-sized drop placed onto the center of the CPU. The CPU cooler product being tested was then laid down flat onto the CPU, and compressed to the motherboard using the supplied retaining mechanism. If the mounting mechanism used only two point of force, they were tightened in alternation; standard clip-style mounting with four securing points were compressed using the cross-over method. Once installed, the system was tested for a baseline reading prior to testing.

At the start of each test, the ambient room temperature was measured to track any fluctuation throughout the testing period. EVEREST Ultimate Engineer Version 4.20.1170 was then utilized to create core loads and measure each individual CPU core temperature. It's important to note that software-based temperature readings reflect the thermistor output as recorded by the BIOS. For this reason, it is critically important to use the exact same software and BIOS versions throughout the entire test cycle, or the results will be incomparable. All of the units compared in our results were tested on the same motherboard using the same BIOS and software, with only the product itself changing in each test. These readings are neither absolute nor calibrated, since every BIOS is programmed differently. Nevertheless, all results are still comparable and relative to each products in our test bed.

One unfortunate problem is that CPU's report temperatures as a whole number and not in fractions. This in turn causes the motherboard BIOS and subsequent software applications such as EVEREST to also report to the nearest whole number. To compensate for this, our tests were conducted several times after complete power down thermal cycles. Conversely, the ambient room temperature levels were all recorded and accurate to one-tenth of a degree Celsius.

Test System

Motherboard: Gigabyte GA-X48T-DQ6 (Intel X48 Chipset) with version F4 BIOS
Processor: Intel E8200 Core 2 Duo 2.66GHz (Overclocked to 3.6 GHz)
System Memory: Corsair PC3-14400 DDR3 1800MHz
Audio: HT Omega Claro Plus+ AD8620BR Op Amp Sound Card
Disk Drive 1: OCZ SATA-II 32GB 2.5-Inch SSD OCZSSD2-1S32G
Disk Drive 2: (Paging File) MemoRight GT MR25.2-064S 2.5-Inch 64GB SATA SSD
Optical Drive: ASUS BC-1205PT SATA Blu-ray Disc Optical Drive
Enclosure: Lian Li PC-B25B Black Aluminum Mid-Tower ATX Case
PSU: ePower Technology EP-1200P10 xScale 1200W PSU
Grpahics: ZOTAC GeForce 9800 GTX 512MB Video Card
Monitor: Honeywell 22-Inch LCD Monitor MT-SY-HWLM2216
Operating System: Windows XP Professional SP-3 (optimized to 16 processes at idle)

Support Equipment

• OCZ Freeze Thermal Interface Material (No curing time necessary or given)
• Noctua 120mm cooling fan, model NF-P12 (54 CFM @ 20 dbA)
• Yate Loon 120mm cooling fan, model D12SH-12 (88 CFM @ 40 dbA)

All of our tests are conducted using two different product orientations: horizontal and vertical. So far as we can tell, Benchmark Reviews is probably the first website to test with this method. We do this because there are different requirements for each persons system, and it's a good idea to know what effect gravity has on the product.

At the start of our test period, the test system is orientated sideways in a flat "HTPC" position which places the motherboard and processor horizontally to face up towards the ceiling. Next, the computer system is powered on and EVEREST system stability tests are started with Stress CPU and Stress FPU options selected. Then for a minimum of ten minutes EVEREST loads each CPU core to 100% usage, which drives the temperature to its highest point. Finally, once temperatures have sustained a plateau, the ending ambient room temperature and CPU core levels are recorded and the first benchmark segment is complete. EVEREST remains running at full load into the next test segment.

The second benchmark segment begins by simply turning the test system vertically upright into a standing tower position, so that the motherboard and CPU are facing to the side. Many of the products we have tested utilize a "U" pattern in the heat-pipe rods, and the upright system orientation favors this particular product design because it removes the effect of gravity on the heat-pipes' thermal cycle. For a minimum of five additional minutes EVEREST continues to load each CPU core, and once temperatures have plateaued the ending ambient room temperature and CPU core levels are recorded. This process was identical for all cooling solutions used in our benchmark tests segments.

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