Introduction

Today we are getting acquainted with a new power supply unit (PSU) manufacturer, Cyonic. It is very likely that most of the people who are reading this review have never heard of the brand before. We should start by mentioning that Cyonic is a brand dealing solely in Seasonic hardware, with Seaonic one of the major PSU manufacturers worldwide. To clarify the arrangement here, Seasonic sells power supplies to companies like Cyonic to sell on and is not an uncommon way of distributing product. Although in some markets Seasonic does sell as their own brand direct to the end user. The Cyonic name and company was founded just two years ago in Asia and is reluctantly making steps into the North American markets. Cyonic's brand profile and mission statement is, in summary, that they are aiming to provide high performance products to advanced PC users. Cyonic currently offers very few products; only three series and nine PSUs total, with three of them exclusively available in Japan.

The other two series that Cyonic currently offers are the AU and AUx. Both of these series consist of three PSUs each, and the units between the two series are essentially identical, with the sole difference being that the AUx models are modular and the AU models are not. Each series has one 450W, one 550W and one 650W model - if you are looking for high power behemoths, Cyonic is the wrong brand name. Furthermore, all three PSUs in each series are based on the same platform. As such, this review of the AU-550x essentially covers the entire lineup of products that Cyonic currently offers.

Packaging and Bundle

Cyonic is supplying the AU-550x into a medium-sized, sturdy cardboard box with a striking yellow artwork theme. It offers ample protection to the small unit and all the basic specification and features are printed on its sides and rear in multiple languages.

A nice number of extra items are bundled with the AU-550x. Cyonic supplies the basic AC power cable, a multilingual manual, a quick installation guide and four black mounting screws, as well as several black cable ties, three long quality cable straps and two case stickers to choose from. Thumbscrews or a small bag for the cables would be nice, but this bundle is still better than most.

The Cyonic AU-550x is a fully modular PSU and every cable is supplied detached from the unit. With the exception of the sleeved 24-pin cable, all of the cables are "flat", ribbon-like, including the supplied Molex to Floppy connector adapter. All of the cables, including the ATX 24-pin cable, are made using black wires and black connectors.

External Appearance

The first thing one will notice about the Cyonic AU-550x is its very small proportions. It is built inside a chassis that is only 140 mm long, allowing it to fit even in the most peculiar cases that have a slot for an ATX PSU. The body is sprayed with a matte black paint and most of the top side is covered by a large sticker with the electrical specifications and certifications of the PSU. There are no stickers on the sides of the chassis, and Cyonic opted to punch the company name onto the metal surface and print the model and company logo using deep purple paint.

The connectors for the modular cables can be found at the front side of the chassis. It is interesting to note that there are three connectors for the 12V CPU and PCI Express cables but only two cables are supplied with the 550W version. A badge with the company logo has been installed above the standard on/off switch and AC cable receptacle at the rear side of the body. A parallel bars finger guard rests above the simple black fan.

Internal Design

Cyonic installed a 120 mm Hong Hua for the cooling needs of the AU-550x. The HA1225M12F-Z is a very powerful 2050 RPM model with a hydrodynamic bearing. Considering the mediocre power output of the PSU and its claimed high efficiency, it should be very difficult to force this fan to run anywhere near its maximum speed.

As it has been already mentioned, Seasonic is the OEM behind Cyonic PSUs. The Cyonic AU-550x (and all six of their currently available models) is based on a platform that looks like Seasonic's G-series, but it is not quite the same. The differences are not dramatic and appear to have been made in order to allow for the vertical board with the connectors to be installed so closely above the main PCB, i.e. to fit the platform inside the 140 mm chassis.

The filtering stage is at the back of the AC receptacle, with the components covered by a metallic shield in order to minimize EMI. We spotted a total of six Y capacitors, two X capacitors and two filtering inductors before the main rectification bridge. The main bridge has a small dedicated heatsink, densely packed next to a larger heatsink and the passive APFC components. There are no components directly attached on the heatsink near the edge of the PCB, as that heatsink is cooling the active components installed at the bottom of the main PCB. The large PFC 420V/470μF capacitor is supplied by Nippon Chemi-Con.

The secondary electrolytic capacitors are supplied by Nippon Chemi-Con as well, with a single capacitor coming from Rubycon. All polymer capacitors are supplied by Fujitsu. The 3.3V and 5V generation circuits were moved towards the AC receptacle and were given a small heatsink each. It is very interesting to note that this is the first unit that we have ever reviewed that makes use of board mount DC/DC converters. Essentially, Cyonic replaced most of the DC to DC conversion circuit with a "brick" converter for each of the two minor lines. These typically are of high efficiency and very compact, although they obviously are much more costly than a typical circuit. The energy is being transferred from the main PCB onto the vertical PCB via a few very thick wires, carefully tied to avoid creating a messy layout. Finally, a lot of glue has been used to maximize the mechanical strength of the PSU.

Cold Test Results

For the testing of PSUs, we are using high precision electronic loads with a maximum power draw of 2700 Watts, a Rigol DS5042M 40 MHz oscilloscope, an Extech 380803 power analyzer, two high precision UNI-T UT-325 digital thermometers, an Extech HD600 SPL meter, a self-designed hotbox and various other bits and parts. For a thorough explanation of our testing methodology and more details on our equipment, please refer to our How We Test PSUs - 2014 Pipeline post.

The efficiency of the AU-550x is very high but not astounding considering that this is an 80Plus Gold certified unit. However, it is improved over the G-series platform we reviewed a while ago. The improvement is not vast but it is well above what we could consider an accuracy or consistency error. The average efficiency within the nominal load range (20% to 100% of the unit's capacity) is 92.5%, with a maximum of 94.2% at 50% load. The efficiency is fairly consistent at higher and lower loads, staying at over 90% across the entire nominal load range. Like all current PC switching PSUs, the efficiency drops sharply at very low loads. We received a reading of 75.8% with a load of 28 Watts (5%), which is actually fairly good for such a low power output.

The very high efficiency allows the Cyonic AU-550x to maintain a rather linear thermal profile. It requires very little cooling at lower loads, therefore the fan speed is kept to a minimum and the PSU remains entirely silent. As the load rises, the thermal management of the PSU steadily increases the speed of the fan to meet the thermal needs of the PSU. Still, even with the PSU fully loaded, there is nothing more than a slight hum coming from the fan, which provides more than enough airflow for the cooling needs of the PSU. 

Hot Test Results

The following tables display surprising results about the electrical performance of the Cyonic AU-550x. Even though the filtering of the minor voltage lines is exceptional, with barely any readable figures at all, the 12V line falls far behind. A maximum ripple of 62 mV at full load is definitely not bad, it is a mere half of the 120 mV design limit, but it is not on par with the astounding performance of the other two main voltage lines. Voltage regulation is fairly good, at 1.5% for the 12 V line and about 2.2% for the 3.3V/5V lines.

We need to mention that this is a PSU rated at 40°C and we perform our testing at temperatures higher than 45°C - we could reduce the ambient temperature of our hotbox testing but we chose not to do so as the results would then not be comparable to those of our previous reviews.

Despite the 40°C temperature rating, higher ambient temperatures do not have a dramatic impact on the electrical performance of the Cyonic AU-550x. The energy conversion efficiency is reduced by about 0.8%, without significant variations across the entire load range of the power supply. Considering the parts that this unit is made of, it is likely that Cyonic just copied the base ATX specifications that dictate a maximum power rating at 40°C and called it a day, even though the PSU can easily output its maximum power at higher temperatures as well.

The internal temperatures of the Cyonic AU-550x increase relatively more than outside the hotbox, but the difference is small and has no effect on the overall performance of the unit. Still, it is apparent that the PSU gets a little hotter than it is supposed to because Cyonic opted for better acoustics performance, forbidding the fan from spinning too fast if the temperatures do not reach critical figures. The heatsinks are also small, even considering the mediocre power output and high efficiency of the unit. Nevertheless, the Cyonic AU-550x maintains tolerable noise figures even in the hellish environment of our hotbox, at the expense of a little higher internal temperatures. 

Conclusion

In our humble opinion, Cyonic started off the right foot as a company. Instead of starting with very high power products, like many other companies did before, they opted to focus on just a few high performance 450-650 Watt PSUs. This power range is where the needs of the vast majority of PC users lie. A typical home/office PC would hardly ever reach a demand greater than 200 Watts and even a good gaming system with a single GPU should not require more than 400-450 Watts at peak power. As all switching PSUs operate best at about 50% load, the Cyonic models are ideal for such systems.

The overall performance of the AU-550x came as a little surprise to us. When we saw the minimal heatsinks and the modified platform, we initially expected it to perform worse than the Seasonic G-series model. True enough, the thermal performance of the AU-550x is slightly worse and it does get a little warmer when it is heavily stressed. However, to our surprise and despite the presence of the secondary vertical PCB and all the losses associated with the extra connections/cables, the Cyonic AU-550x is still a little more efficient than the standard platform it is based on. It also resists very high temperatures and can still deliver very good performance under very harsh conditions. The higher efficiency combats the heatsink mass reduction and allows the Cyonic AU-550x to maintain very low noise levels. The company could make the thermal control of the PSU more aggressive, with the fan speeding up faster and forcing it to maintain lower internal temperatures, but opted for excellent acoustics performance instead. Considering the very high quality components that this PSU is made of, we believe that is was a good trade-off.

When it comes to electrical performance, we were bewildered to see the massive difference between the minor voltage lines and the main 12V line. We had to repeat our tests several times just to make sure. The filtering of the 3.3V/5V lines is one of the best that we have ever seen, if not the best, with our instruments hardly capable of recording any ripple at all. On the other hand, the 12V line is well filtered, but nowhere near as perfectly as the minor voltage lines. The presence of very high quality capacitors throughout the design makes this even stranger, as it implies that the ripple does not come from the mediocre capabilities of an average capacitor. Nevertheless, even the maximum ripple that the 12 V line displayed was half that of the ATX design limit, so we should stress that this is not really a problem, just a peculiar characteristic of this particular PSU.

In summary, the Cyonic AU-550x does very well and we feel that the newly founded company started off with some very interesting products that are targeted at a wide audience. With a retail price of $90 plus shipping, the Cyonic AU-550x is well-priced as well. Most quality 80Plus Gold certified 550 Watts PSUs are currently retailing for $80-120, so that does not make the Cyonic AU-550x an astonishing deal but, considering its performance, quality and design, it certainly earns our recommendation.