Monsoon II Lite: Thermal Electric Cooling Tower

Noise

For some users the goal is maximum stable overclock, and they will live with the inconvenience of a louder system. For others silence is the most important factor, and these users will forgo maximum overclocking if this increases system noise levels. In general you might expect a solid-state cooling device to be very quiet, but the results with the Monsoon II Lite were mixed.

The 92mm cooling fan on the Monsoon II is extremely quiet at low speeds, below the noise floor of the test system. It is also relatively quiet at higher speeds, and comparable to other high-end units at maximum speed. However, both the TEC operation and the fan speed of the Monsoon II Lite are controlled by the PCI controller card. With this in mind, test conditions had to be changed a bit to realistically measure noise on the Monsoon II.

Noise was finally measured at low speed idle, and also measured under high overclock stress to get a range of noise that might be expected when running a Monsoon Lite II. Other noise measurement conditions were the same as used in previous cooling noise tests. This means noise levels below the noise floor of our test system with a quiet 520W power supply are ignored.

There are virtually no power supplies that do not have a fan. While Zalman and a few others do make a few 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 power supply was measured. The power supply used for the cooling test bed was the OCZ PowerStream 520, which is one of the quieter of the high performance power supplies. The noise level of the power supply was 38.3dB from 24" (61cm) and 47dB from 6" (152mm). The measured noise level of the test room is 36.4dB, which would be considered a relatively quiet room with a noise floor slightly below the OCZ PowerStream 520 PSU.



Measured noise levels in this chart should be considered worst case. Measurements were 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.

Despite the fact that the fan itself is capable of running quietly, the noise measurements for the Monsoon II Lite were very mixed. Under idle conditions the noise level is average among quiet tower units. However, stress condition noise measurements were among the worst measured so far in our cooler tests. The reason for this is the way the fan is controlled by the PCI card. During idle at normal speeds the TEC is not even active and the Monsoon II is quiet. However, during operations where the TEC is turning on, half power, and off, the fan is also starting, stopping, and running at reduced speed - in conjunction with the TEC. This does not seriously impact performance, but it causes a huge amount of clicking and buzzing which dramatically increases noise.

This was brought to the attention of Vigor Gaming who stated they are aware of the problem. Vigor told us they are working on a fix to separately control the fan and TEC with the controller card which should effectively address this issue. When asked for a timetable we were told the revised until should be available in 3 to 4 months.

As already stated, this starting, stopping, and slowing of the fan does not appear to seriously impact performance. It is also interesting that this increased noise only happens in "in-between" states. At normal idle with the TEC off or at high stress with the TEC mostly on the problem is minimal. Under in-between conditions, however, the clicking and buzzing can be very annoying.