After reinstalling the motherboard into our case and plugging the Swiftech fan into the board's 4-pin header, I set the SmartFan function in the BIOS to use the minimum fan speed setting with the lowest temperature ceiling. With the MSI this means a 12.5% idle fan speed until a temperature of 40°C is reached, at which point the fan speed will increase. These are the same settings I use for the Swiftech MCP35X pump in the Edge water cooling kit, which yields the lowest possible noise at idle, but will quickly ramp up speed under load.
The OCCT CPU test was used to load all six cores of the 1090T X6 at close to 100% for an hour. Although OCCT logs the CPU temp during the test, this reading is taken from the thermal diode inside the core, which has been reported to be miscalibrated in many of the Thuban processors. In the OCCT graphs below, an idle temperature as low as 15°C is recorded. Since the room temp hovered at 72°-74°F during testing, it's obviously impossible to have a CPU temp below ambient with this system. Therefore MSI Control Center was used to log the temperature as detected by the motherboard sensor for the CPU. It shows a temp of 25°C (76°F) at idle, and is likely the more accurate reading to go by.
The Polaris 120 manages to keep the AMD X6 1090T processor at a cool 25°C at idle, only one degree more than our Edge kit. Under full load, the Polaris still manages to keep things reasonably cool, registering a maximum temperature of 44°C as recorded by the MSI board sensor. The temperature mainly fluctuated between 41°C - 43°C and the fan speed bounced between 2000 and 2300RPM, reaching a maximum of around 2350RPM, not quite at full speed. Although very quiet at an idle speed of 1200RPM, the fan quickly became noticeable outside the case above 2000RPM, and fairly noisy running near full tilt. Seeing as how this was with all six cores loaded at 100% however, something you're not likely to experience in a real-world scenario, the fan will likely remain at a lower, much more tolerable speed.
Boosting the CPU up to 4.2Ghz at more than 1.45v with the board overvolting above that, the Swiftech Polaris still performed quite well. Although it did fall behind the Edge kit by more than a few degrees, the important fact is that it kept the CPU stable at load for the duration of the hour-long test. Not very many air coolers can accomplish a feat like that, and it's possible that with a little more tweaking I may have even been able to squeeze a bit more speed from the chip. But to keep things in line with our previous tests, we'll stop there and call it a day.
Let's wrap things up with some final thoughts and conclusion.