Corsair HX1000W (CMPSU-1000HX)
I will end this roundup with the HX1000W model. As its name suggests, it has an output power of 1000 watts.
The PSU comes in an impressively large box, almost 40 centimeters long. Besides the PSU proper, the box contains a neat pouch with detachable cables and a set of traditional trifles such as single-use nylon straps, screws and a Powered by Corsair sticker.
The PSU is up to the box in its dimensions, measuring 200 millimeters of length, which is 55 millimeters longer than a standard ATX power supply. Well, I don’t think that someone will buy a 1000W power supply to install it into a compact system case.
The HX1000W is covered with black matte paint that feels somewhat rough to your fingers. The U-shaped cover is secured with eight rather than four screws as usual, although the steel of the case is thick enough to avoid any rattle.
The interior design looks familiar to me. It is the same as the design of Thermaltake’s 1200 and 1500W models. This power supply is surely developed and manufactured by CWT. And its circuit design is quite original as modern PSUs go.
The HX1000W is actually not one but two power supplies inside. The only common things between these two power supplies are the housing and the input filter. The photo shows clearly that the PSU is symmetrical inside, its left and right parts being identical: two identical active PFC chokes, two identical high-voltage capacitors, two identical transformers, and the same pairs of heatsinks.
This design is really unique. I have only met it in power supplies developed by CWT so far. Although power supplies with two power transformers are nothing new today, the two transformers in them have common circuitry for voltage control and regulation, common power transistors, diodes and other components. Here, we have not just a dual-transformer PSU but two individual 500W power supplies assembled in a single housing. In fact, you can even shut down one of them, and the other will go on working, yielding its 500 watts.
Well, the HX1000W does not offer such a half-wattage mode due to one reason. Its sub-PSUs are not exactly identical. Each of them yields two voltages, but one provides +12V and +5V whereas the other provides +12V and +3.3V. That’s why you wouldn’t be able to power your PC up using only one of these sub-PSUs.
The PWM controllers are located on small individual cards, one for each sub-PSU. They are based on the popular Champion Micro CM6800G chip that combines two controllers (for active PFC and the main regulator).
+12V is the main voltage of each sub-PSU. The +5V and +3.3V voltages are produced from +12V by means of rather low-power individual switching converters located on small individual cards. Each such converter is in fact a miniature power supply, but without an input rectifier. It has direct current at the input. The card carries a controller chip, power transistors of the converter and synchronous rectifier, a choke and smoothing capacitors. Thanks to the high operating frequency, the use of synchronous rectifiers and the rather low permissible load, these mini-converters do not require any additional cooling. This design is original but not exactly new. I have seen such regulators in some expensive PSUs. According to the developers, they ensure a quicker and more accurate reaction to changes in the load than what can be achieved with cheaper auxiliary regulators based on saturated-core chokes that are traditionally used in PSUs with dedicated voltage regulation.
The PSU is cooled with one 120mm fan running on ball bearings (Yate Loon D14BH-12, 2800rpm).