Corsair VX550W (CMPSU-550VX)
The next product from Corsair to be discussed here belongs to the same inexpensive VX series but is declared to have an output power of 550W.
The personal color of this PSU is bright orange. It resembles the TX750W in the photos you can see on the Corsair website, but the latter is actually brown and far less bright.
The accessories are the same as you get with the VX450W: screws, single-use straps, a Powered by Corsair sticker, pouch, user manual, and power cord.
The VX450W and the VX550W resemble each other at first glance only, due to the same matte black paint. If you look at them closely, you can note the different position of the switch, the different shape of the case panels, and even the different way the fan grid is fastened to the case.
What is the reason for such small but obvious discrepancies between two PSUs from the same series?
Well, the interior design of the VX550W provides an immediate answer. This PSU is manufactured by Channel Well Technology (CWT) and not by Seasonic. The name of CWT should be familiar to our readers because we have tested its products under the brands of Antec (although Antec has recently switched from CWT to Seasonic), Thermaltake and many others. The above-mentioned Corsair TX750W is manufactured at Channel Well’s facilities, too.
It is, however, odd to see PSUs from two different makers in the same product series. Are these models so similar that the buyers won’t see any difference save for the extra 100W? Let’s see…
The component layout of the VX550W seems to be the same as that of the VX450W. There are three heatsinks with transistors and diode packs, one power transformer, and a PWM regulator on an individual card. Some details are just placed in somewhat different ways.
Still, it is possible to spot at least one point of dissimilarity. There are three (not two as in the VX450W) large toroidal chokes under the output cables and the nearby heatsink. You can see only one choke in the photo – the other two are hidden under the bundles of cables and the additional card. The three chokes mean that the PSU has dedicated voltage regulation: there is one choke responsible for each of the three main output lines.
That’s the only significant difference between the two PSUs, though. Like the VX450W, this model has active PFC which is based on a CM6800G controller that is located on an individual small card. This chip also serves as a controller of the PSU’s main regulator.
The heatsinks are made from aluminum bars painted black. They are about 3 millimeters thick at the top and about 5 millimeters thick at the bottom. The transistors and diode packs have large TO-247 packages. They are installed via insulating pads only – without additional plates or anything.
There are KZE series electrolytic capacitors from United Chemi-Con at the PSU’s output. The capacitors are rated for a temperature of 105°C (they do not get as hot as that, of course, but the higher temperature rating ensures a longer service life for them). A 440V/330µF Hitachi HU4 capacitor is installed at the input.
The PSU is cooled with a 120x120x25mm fan (Adda AD1212HB-A71GL, 2200rpm). The rated speed of the fan is higher than in the VX450W. Almost half of the fan is covered with a piece of celluloid film. As I wrote above, this is necessary for optimal distribution of airflows inside the PSU case. Without this film, there would be a zone with high pressure but slow airflow at the back part of the case, near the almost blank panel. It may sound paradoxical, but blocking a part of the fan’s impeller increases the efficiency of cooling!
By the way, this is a good illustration of the fact that a large fan does not necessarily cool better although many manufacturers tout 140mm fans as an indisputable advantage.