The Cyonic AU-550x PSU Review
by E. Fylladitakis on August 17, 2015 8:00 AM EST- Posted in
- Cases/Cooling/PSUs
- Seasonic
- PSUs
- 550W
- Cyonic
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.
| Main Output | ||||||||
| Load (Watts) | 111.65 W | 277.72 W | 414.04 W | 548.99 W | ||||
| Load (Percent) | 20.3% | 50.5% | 75.28% | 99.82% | ||||
| Amperes | Volts | Amperes | Volts | Amperes | Volts | Amperes | Volts | |
| 3.3 V | 1.77 | 3.38 | 4.41 | 3.37 | 6.62 | 3.32 | 8.83 | 3.32 |
| 5 V | 1.77 | 5.17 | 4.41 | 5.16 | 6.62 | 5.07 | 8.83 | 5.04 |
| 12 V | 7.95 | 12.14 | 19.86 | 12.09 | 29.8 | 12.03 | 39.73 | 11.96 |
| Line | Regulation (20% to 100% load) |
Voltage Ripple (mV) | |||||
| 20% Load | 50% Load | 75% Load | 100% Load | CL1 12V |
CL2 3.3V + 5V |
||
| 3.3V | 1.9% | 4 | 6 | 6 | 8 | 4 | 8 |
| 5V | 2.4% | 4 | 6 | 6 | 8 | 4 | 8 |
| 12V | 1.5% | 18 | 24 | 40 | 62 | 60 | 26 |
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.
Facebook
Twitter
RSS
30 Comments
View All Comments
marraco - Monday, August 17, 2015 - link
Anandtech needs to learn a lot about reviewing a PSU.Where are the power on tests? They are critical.
How does it behaves when each rail is fully loaded? Does it really deliver? Most PSU don't.
How much AC noise and ripple contains the signal under different loads? Those small peaks may slowly erode your hardware
E.Fyll - Monday, August 17, 2015 - link
By "Power On" tests, I assume that you are talking about the AC input and care about the inrush current and harmonics.Power On tests require a very good oscilloscope with current probes and a programmable AC source. These are equipment in the tens of thousands of dollars. Although there are plans to purchase them in the future, you need to excuse me that I do not possess such funds to spend for just a couple of more tests.
...and not practically useful tests either. Power On tests are everything but "critical". They are virtually limited to compliance certification. The inrush current or the harmonics generated by a PSU will not affect its performance. Harmonics may affect other very sensitive devices on the same line, such as audio equipment, but again these need to reach extraordinary levels to become an issue. Inrush current could cause your household circuit breaker to release if it is too high, but 99.99999999% of the readers cannot really calculate and compare the current-time (I-t) curve of a PSU against the I-t curve of the circuit breaker. If I gave them a curve with a maximum current of 170A over a few nanoseconds, most people would think that their house would catch fire, even though that figure is entirely unimportant. 99.99% cannot even differentiate between power and energy, they cannot comprehend that timeless figures do not tell any side of the story at all.
Now, if you are talking on the DC side, they become critical only if they fail their required specifications. It is very difficult for a PSU not to meet these standards. Once again, a very fast oscilloscope is required for proper testing, but I would report it if something was amiss with the oscilloscope that I am using right now.
The vast majority (99.9% or more) of the PSUs will behave just fine with each rail loaded to its maximum wattage and current specifications. Heavy ripple may appear due to the cross-loading, but I never saw a single PSU that would not work. We have the cross-loading tests just for that. And, by the way, loading a single rail to the maximum while the rest are unloaded is not a proper usage scenario. By that logic, I should be testing them on mount Everest, just to see if they can work at an altitude of 5000 meters. Even for our cross loading tests, the load is terribly unbalanced and it is virtually impossible to represent a real world scenario. Well, unless if what you want to do is to use a PSU to start a car's engine or to power a welder.
And since we are on the topic of learning, you can have AC signal on your DC signal (that's ripple) and random fluctuations (that's noise). Page 4 for ripple. For noise, once again you need a VERY expensive oscilloscope, capable of calculating and displaying ripple and noise separately. My equipment cannot currently filter the noise out of a signal.
And yes, ripple is one of the most important PSU characteristics in my opinion, as it has a significant effect on the lifetime of electronics.
ImSpartacus - Tuesday, August 18, 2015 - link
Whoa, let's calm down there, hondo.It's not worth arguing with random people on the internet.
It's good to read comments and feedback, but spend your time writing articles, not massive comments.
dqniel - Tuesday, August 18, 2015 - link
His comment was filled with useful information, so I'm glad he posted it.marraco - Monday, August 24, 2015 - link
Thanks for your answer.I apologize, because for some reason I didn't noticed the ripple data in page 4. Thanks for including it.
Some sites specialized on PSU analysis compare each unit with the certificated specification standards, and other units.
I learnt about the importance of ripple and power on behavior when one of my motherboards died, and a friend told me that my PSU had bad behavior, so the ripple probably damaged it enough for the bad peaks at power on to finish the work.
He was working at a university, so he didn’t pay for the equipment. I didn’t knew that it was so expensive.
I'm sorry to hear that you do not have that expensive equipment. I'm accostumed to find here reviews of expensive hardware, and forgot that generally it is lendt or donated by manufacturers.
kuttan - Monday, August 24, 2015 - link
No worry here a good review which is easy to understand and informative. So sites go too much technical in a sense that you need to poses a PhD in electrical science to understand what they say. Some sites do review the opposite way that they do some basic load tests and efficiency tests I'm not naming it who. Anandtech PSU reviews are overall balanced and yet detailed enough.Folterknecht - Monday, August 17, 2015 - link
Can't remember when/if I saw a Seasonic (based) PSU with 60 mV Ripple, that usually their strong point - bad Sample?@jonnyGURU:
If you 're working for Corsair now - that's at least what I assume after seeing you in a Techsyndikate Interview regarding single/multi rail designs "recently" - commenting on on a competitiors product seems odd to me.
sheh - Tuesday, August 18, 2015 - link
I still think it would be useful to test with a 50W load, and even 25W. Modern computers don't use much power in light usage.Beaver M. - Tuesday, August 18, 2015 - link
Exactly. A test like that is mandatory nowadays. You can actually get systems down to 10-15W, if you put some effort into it.DanNeely - Wednesday, August 19, 2015 - link
It was tested at a sub 50W load. Eyeballing it I'd say it's at most 30W; might only be 25.