Upon opening up the OCZ x PC P&C 850W Mk III Silencer, it is apparent that this is no generic computer power supply. The PSU is all about power and cooling capabilities with minimal noise as suggested by the manufacturers.
The first object of notice is the 140mm 0.40A double ball-bearing Globefan. This fan brand is based out of Taiwan and is widely used in many power supply builds, as well as many other consumer-level electronic products. The equipped 140mm fan is specifically labelled as the RL4Z B1402512H model (12V, 102.4 CFM, 34 dBA, up to 1500 RPM), and provides the more than adequate airflow coverage for the 850W Mk III Silencer.
The larger fan is specific to the new Mk III Silencer design, not only to provide quite an increased airflow compared to other power supply models with smaller fan diameters, but also to allow lower RPM values thereby decreasing the noise from the fan. As we all know, nobody likes a power supply which produces the nauseating hum and becomes unbearable to withstand after a mere few weeks.
The Mk III Silencer features a new design to further curb fan noise, the feature aptly named ‘silent mode’, compared to the default ‘normal mode’ which is seen in most power supply models. In the Mk III Silencer, a switching system built into the power supply allows for the fan to only come on when at least 50% load is achieved on the power supply, at which time the speed of the fan varies by the load and temperature values within the power supply case.
Silent mode allows for the preservation of both energy and the fan, compared to the normal mode, which allows the fan to always spin and varies by the load and temperature once the power supply becomes active.
This is a brilliant design which not only allows for the 850W Mk III Silencer to remain silent for the most part (considering it is not 100% passive), but also allows for increased longevity. In a power supply the fan is usually the first part to cease and stop working due to the build-up of dust within the casing (due to the fan constantly running). As a result a chain effect ensues which sees the temperature of the power supply increase, which ultimately causes the power supply to overheat and cause a variety of components to fail (burn-out). Therefore to reiterate the importance, silence mode is a great feature seen on the Mk III Silencer power supply which helps to alleviate these issues.
Moving on, we can see the two large heatsinks that separate the transformers from the primary and secondary power supply regions. The heatsinks are actually thinner and shorter in the Mk III Silencer, thus allowing for quicker heat dispersion as the fan is found directly above to quickly move and dissipate heat.