CoolerMaster RealPower RS-550-ACLY (550W)
I can’t but draw a parallel here. Almost one year ago we published a review in which a 450W power supply model from CoolerMaster was tested second after an A.C.Ryan Ryanpower2 ACR-PS2094 – the junior brother of the above-described ACR-PS2100! So, once again we’ve got RealPower and Ryanpower2 power supplies in the same review, but they have grown 100 watts more powerful now. This extra wattage doesn’t help the Ryanpower2 much as you’ve just seen. What about the RealPower?
The power supply is in a steel case, painted a lusterless black color. It is cooled with a single 120mm fan and lacks a 110/230V switch – just like the Ryanpower2, but for another reason. The RS-550-ACLY features an active PFC device that supports a full range of input AC voltages from 90 to 265V.
The real manufacturer of this PSU is AcBel Polytech Inc., which is indicated by the UL certificate number on the label: E131875.
The PSU doesn’t have detachable cables and there is no protective plastic ring where they go out of the case, just a hole with a rolled-in edge. Some users have reported their concern that the cable insulation may wear off against the edge of the case with time, that’s why I mention this at all. Personally I do not think the cables can be damaged under normal use and don’t see any big difference between a plastic ring and a rolled-in edge of the case.
The unit is analogous to its 450W predecessor on the inside, with active PFC (a Fairchild ML4800CP chip is employed which combines PFC and main regulator controllers; it is the chip with the blue paper label in the snapshot) and group voltage regulation. So, this is quite a regular power supply as they are today. A curious thing is that the PFC choke is wound on an E-type rather than on a toroidal core (in the bottom left corner of the first snapshot). A non-typical thing too is the ferrite ring with a brown-wire loop inside that you can see in the top left corner of the snapshot. This is a current transformer the power consumption indicator, which is to be installed in the front panel of your system case, is attached to.
Don’t be misled by those two tall high-voltage capacitors into thinking that the RS-550ACLY is a classic-design unit with two capacitors connected in series. Both the capacitors are for 450V voltage (the operating voltage on the active PFC’s output is about 400W irrespective of the input voltage) and are connected in parallel, yielding a combined capacitance of 2*150=300µF.
You receive a power consumption indicator along with the power supply. It is inserted into a 3.5” bay of your system case. The box with the indicator contains a micro-ammeter and a blue highlighting LED; it works only with this particular power supply. Owners of light-colored system cases can replace the indicator’s faceplate with a silvery one, which is also included. The showings aren’t very accurate since the indicator has a rude scale and is also not a very high-precision measuring instrument, either. So, it should be rather viewed as decoration. I must acknowledge, however, that the indicator did report the power consumption of the PSU correctly at loads of about 300W. It would yield exaggerated numbers at higher loads and understated ones at lower loads.
CoolerMaster cunningly declares peak currents far above typical currents for the three 12V lines. What’s the hitch? Like with any other ATX12V 2.0 power supply, you should rather look at the combined power of the 12V power rail. It is 360W here, so the combined current in all the three 12V lines cannot be higher than 30A whether it is a peak or not.