Corsair’s description of its RM power supply family is very matter-of-fact. Gold-certified and fully modular are the two phrases used for marketing, and there's not much else to add except maybe that these PSUs are also optimized for quiet operation. After all, Corsair does enable hybrid fan control, meaning the fan stops when temperatures are low enough to support passive cooling. The outcome, of course, is silent operation in those cases (at least, that's how it's supposed to work in theory).
In any case, Corsair's build quality is good and the materials used are excellent. The RM450's matte black finish and rounded edges look nice, though the chassis isn't as compact as Cooler Master's and Seasonic's competing products. All of the bundled cables are modular and flat. As far as cable length and available leads go, Corsair lands in the middle of the pack. Its single +12 V rail is good for up to 37.5 A, according to the company's specifications. As we’ve seen before, the PSU comes with a five-year warranty.
|AC Input||100-240 V, 47-63 Hz|
|DC Output||+3.3 V||+5 V||+12 V (#1)||+12 V (#2)||+12 V (#3)||+12 V (#4)||-12 V||+5 Vsb|
|24 A||22 A||37.5 A||N/A||N/A||N/A||0.8 A||3.0 A|
|Individual Output||9 W||1 W|
|Rail Utilization||Sys||Sys||CPU & VGA|
|Combined Output||110 W||450 W|
|Total Continuous Output||450 W|
A fully modular configuration has the advantage of more flexibility, especially when you need more specialized cables. The flip side of the coin, however, is an efficiency loss. Additional boards, conducting paths, and connectors all have a cumulatively negative impact on this important criteria.
As we might have expected, then, the measurements required for 80 PLUS Gold certification are a close call for the RM450. It manages to hit the three necessary benchmarks with no room to spare whatsoever. Lower loads look worse though, and those are what a normal PC will deal with most of the time. At 50 W, Corsair achieves an efficiency level of 80 percent. This drops all the way to 72 percent at 25 W.
Hold-up time is one of the RM450’s strengths, registering 24 ms. The ripple and noise measurements also speak to this power supply's high quality; they're similar to what we saw from Cooler Master's V450S. We also saw very low power consumption (.04 W) at standby without any load, which is great.
Thus far, Corsair's RM450 looks great. And, due to its dynamic fan control, it should also sail through our acoustic measurements. Then again, we’ve seen power supplies marketed as semi-passive that ended up sounding like hair dryers when their fans spun up.
Fortunately, Corsair's RM450 doesn't disappoint. Under a 200 W load, the fan didn't spin, and after 30 minutes of heat build-up, we were still waiting for it to make noise. We finally triggered the fan at 360 W, and even then it only generated a barely-noticeable 30.4 dB(A).
A Look at the PCB
Corsair has been working with CWT for years, and the RM family is a product of that collaboration. The chassis' build quality is high, similar to everything we find inside.
The input filter is separated into two parts consisting of two X and four Y capacitors, which work in conjunction with a MOV and two choke coils. The primary capacitor is made by Panasonic yet again. We find secondary ones from Nippon Chemi-Con and CapXon, the latter of which seems to be a popular Chinese supplier these days.
Corsair also uses a DC-to-DC converter topology, but skips the LLC and uses a somewhat dated IC instead. Nevertheless, this configuration is good enough to earn that Gold certification. Solder quality is consistent with what you should expect in this price category.