Testbed and Methods
The tests were performed in a closed system case. Our testbed was configured as follows:
- Mainboard: Intel Siler DX79SI (Intel X79 Express, LGA 2011, BIOS 0460 from 03/27/2012);
- CPU: Intel Core i7-3960X Extreme Edition, 3.3 GHz, 1.2 V, 6 x 256 KB L2, 15 MB L3 (Sandy Bridge-E, C1, 32 nm);
- Thermal interface: ARCTIC MX-4;
- System memory: DDR3 4 x 4GB Mushkin Redline (Spec: 2133 MHz / 9-11-10-28 / 1.65 V);
- Graphics card: AMD Radeon HD 7770 GHz Edition 1 GB/128 bit GDDR5, 1000/4500 MHz and 1100/4500 MHz;
- System drive: Crucial m4 256 GB SSD (SATA-III,CT256M4SSD2, BIOS v0009);
- Drive for programs and games: Western Digital VelociRaptor (300GB, SATA-II, 10000 RPM, 16MB cache, NCQ) inside Scythe Quiet Drive 3.5” HDD silencer and cooler;
- Backup drive: Samsung Ecogreen F4 HD204UI (SATA-II, 2 TB, 5400 RPM, 32 MB, NCQ);
- System case: Antec Twelve Hundred (front panel: three Noiseblocker NB-Multiframe S-Series MF12-S2 fans at 1020 RPM; back panel: two Noiseblocker NB-BlackSilent PRO PL-1 fans at 1020 RPM; top panel: standard 200 mm fan at 400 RPM);
- Control and monitoring panel: Zalman ZM-MFC3;
- Power supply: Xigmatek “No Rules Power” NRP-HC1501 1500 W (with a default 140 mm fan).
The graphics card is equipped with a reference cooler featuring a plastic casing, aluminum heatsink and a PWM fan:
We thought that 1 GHz GPU frequency wouldn’t be enough to properly test the cooling efficiency of our testing participants, therefore, we overclocked our graphics card to 1.1 GHz without adjusting its voltage in any way:
The testing programs were installed under Microsoft Windows 7 Ultimate x64 SP1. We used DirectX End-User Runtimes libraries (from November 2010), as well as AMD Catalyst 12.3 graphics card drivers. We used five runs of Aliens vs. Predator game in 2560x1600 resolution and with maximum image quality settings, 16x anisotropic filtering but without antialiasing, which should allow to load the GPU heavier:
With the settings we used this test loads even a powerful graphics accelerator very heavily, but can’t damage it, which could be the case with FurMark (that is why we decided not to use this benchmark fully in our test session).
The tests were run at least twice. The temperature stabilization period between the two test cycles was about 10-12 minutes. The ambient temperature was checked next to the system case with an electronic thermometer with 0.1°C precision that allows monitoring the temperature changes over the past 6 hours. During our test session room temperature stayed around 25.5-25.6°C. We used our in-house controller to adjust the rotation speed of the fans. The reference cooler on the AMD graphics card featured a PWM-controlled fan, which allowed adjusting its rotation speed automatically.
The noise level of each cooler was measured between 1:00 and 3:00 AM in a closed room about 20 m2 big using CENTER-321 electronic noise meter. The noise level for each cooler was tested outside the system case when the only noise sources in the lab were the cooler and its fan. The noise meter was installed on a tripod and was always at a 150 mm distance from the cooler fan rotor. The tested cooling systems were placed at the edge of the desk on a sheet of polyurethane foam. The lowest noise reading our noise meter device can register is 29.8 dBA and the subjectively comfortable noise level in these testing conditions was around 36 dBA (do not mix it up with low noise level).
Now let’s check out the results of our tests.