Fan Speed Management
The four PSUs are all equipped with identical fans (Yate Loon D14BH-12). About half of the fan is covered with a piece of plastic film near the external panel of the case. This film helps distribute the air flow inside the PSU in a better way. Without it, the back part of the PSU, near a blank panel, would be cooled worse than the front part.
The fan has 140x140x25mm form-factor and a rated speed of 2800rpm. That’s quite a high speed. Let’s see how the fan speed management works, though.
The fan of the 650W model starts up at a speed of 1100rpm and maintains it until a load of 350W. Then it begins to accelerate. At a load of about 600W, the fan reaches its top speed, which is lower than those 2800rpm specified at the Yate Loon website.
The 700W model behaves in the same way. The differences from the 650W unit are insignificant and due to variations in their component ratings.
The 750W model has the same correlation between the fan speed and load. Its fan reaches its top speed at a load of 600W, too.
The enlarged heatsinks of the 850W model do not affect its noisiness in comparison with the lower-wattage models in the series: the fan speed is somewhat higher than 1100rpm at low loads, then grows up linearly, and then reaches its maximum at a load of 600W.
Thus, the Turbo Series models are all average in terms of noisiness. They are comfortable, but not exactly silent, at loads below 300W and rather noisy at 400-500W. There is no difference between the different-wattage models of this series in terms of noise they produce.
Efficiency and Power Factor
After the previous tests it should be obvious enough that these PSUs are going to have identical efficiency. This is indeed so. So I will only show you one diagram:
The PSUs are more than 80% efficient, reaching 86% at the maximum. That’s a very good result even by today’s standards.
Chieftec’s Turbo Series products are very good overall. They deliver perfectly stable voltages, have low output voltage ripple, and boast excellent efficiency. The only downside is that they are not stable together with UPSes (but there is no total incompatibility), produce an average amount of noise, and have few SATA power connectors.
The actual maker of these power supplies is Channel Well, which also makes a considerable part of the produce of Thermaltake, Corsair, Hiper and many other famous brands. In other words, there are very many actually identical power supplies on the market today which only differ in packaging, accessories and connectors. Therefore it is unclear to me why Chieftec thinks it normal for its 850W model to have only four SATA connectors whereas similar products from the opponent brands have six or even eight.
Well, if you don’t plan to install more than two hard disk drives into your computer, Chieftec’s Turbo Series power supplies are going to be a good choice for a fast gaming station.