Self-Contained Water Coolers: Xigmatek AIO vs. Evercool Silver Knight

Noise

For many enthusiasts upgrading cooling the goal is maximum stable overclock, and they will live with the inconvenience of a louder system. For other users silence is the most important factor, and these users will forgo maximum overclocking if that increases system noise levels.

There are very few power supplies that do not have a fan. While Zalman and a few others do make expensive fanless power supplies, we have not seen a fanless unit larger than 500W, or one that would be used for seriously overclocking a system. With that in mind the noise level of the system with all fans turned off except the PSU was measured. The power supply used for the cooling test bed is the OCZ PowerStream 520, which is one of the quieter high performance power supplies.

We have also measured the Corsair 620W and Mushkin 650W power supplies which are reported to be quieter than the OCZ. Both the Corsair and Mushkin are indeed quieter at idle or start up speed. However, as soon as load testing begins and the PSU fan speed kicks up the measured noise level is almost exactly the same as the OCZ PowerStream 520W.

We are currently in the process of reevaluating our cooler test bed and planning some updates. The new configuration will include a "quieter" power supply with variable speed and noise levels. We will also update to a P35 chipset motherboard with all passive cooling to the chipset. Changes to the test bed will appear as part of a future roundup with the motherboard, PSU, and CPU all upgraded to more current configurations. We are also investigating a change to a quad-core processor as a further challenge to CPU cooling.

The noise level of the power supply is 38.3 dB from 24" (61cm) and 47 dB from 6" (152mm). The measured noise level of the test room is 36.4 dB, which is a relatively quiet room with a noise floor slightly below that of the OCZ PowerStream 520 PSU.

Noise levels are measured with the test coolers with fans at both low and high speeds. Both measurements were taken at 6" and 24" above the cooling fan on an open case side. Results are then compared to the other coolers/fans tested in this category. Measured noise levels in this chart should be considered worst case. Measurements are taken with an open side of a mid tower case 6" and 24" from the HSF. Real world would be a completely closed case with a further reduction in noise. Please look for both low and high speed results in the noise graphs.




Water cooling enjoys a well-deserved reputation for silence. We were therefore expecting noise performance at least as good as the better air coolers. The Xigmatek AIO comes close to this performance expectation, staying near or below the system noise floor at both low and high speeds. This is particularly amazing considering the Xigmatek is based on a smaller, higher RPM 80mm fan.

The Evercool Silver Knight, however, has to be considered a disappointment in the area of noise. The Silver Knight uses a larger 92mm fan and a physically larger pump, but it's still quite a bit noisier than the Xigmatek. The measured noise levels at 6" and 24" should tell you to stay away from Silver Knight if you are looking for quiet. Both the fan and water pump are noisier than we would expect with a water system. Noise levels at the tested high fan speeds are much higher than the measured noise with the best air coolers. When turned down to low speed noise levels of the Evercool are below the noise floor, but performance drops below what is already a pretty mediocre performance curve. We expect better from a design as innovative as the Silver Knight.