Specifications

JANUARY 2005 MAXIMUMPC 55
Cooler Master RS-450-ACLY
The ideal power supply for those concerned about
electricity bills
Electricity bills got you down? We know how you feel. Owning a kick-ass rig
doesn’t just mean paying more for parts up front; it also means footing higher
utility bills ad infi nitum. Unless you’re running Cooler Master’s RS-450-ACLY
450-watt power supply, that is. While this PSU didn’t lead in our torture tests,
it was strikingly effi cient, energy-wise.
During our load test, the other power supplies in this roundup typically
consumed anywhere from 363 watts (for the OCZ) to 385 watts (for our generic
reference point), with occasional spikes as high as 406 watts. Imagine our
shock when the Cooler Master cruised through our load test while drawing
an average of just 335 watts of power! At fi rst, we were sure we’d done
something wrong, but after double- and triple-checking our results, we simply
had to conclude that the RS-450-ACLY is astoundingly energy effi cient.
We do feel that Cooler Master could have done a better job of voltage
accuracy, however; our measurements indicated an output voltage of 12.28V
on the PSU’s 12V line. For most people, this discrepancy should be no cause for
concern, but it doesn’t hold a candle to the mere 0.08V delta exhibited by the
NeoPower and TurboCool units we reviewed. It’s also conceivable that the RS-
450-ACLY’s unremarkable voltage accuracy could limit overclocking headroom.
The RS-450-ACLY ships with a nifty wattmeter that fits in a 3.5-inch
drive bay. Active power factor correction and Serial ATA support are
included, but regrettably, PCI Express support is not. Although the power
cables aren’t sleeved or modular, they do feature nice squeezable plugs
that are easy to remove. When it comes to noise management, the
RS-450-ACLY excels. With its thermally controlled 120mm intake fan, it
ranked as one of the quietest
power supplies we reviewed.
While it falls short of
the high bar set by Antec’s
NeoPower and PC Power &
Cooling’s TurboCool, the RS-
450-ACLY is a quality PSU in its
own right. It lacks a few key
features, but gets a boost in our
rankings thanks to fi rst-class
energy effi ciency.
Impressive energy efficiency, quiet, and includes a
wattage meter.
BEACH
BIATCH
Voltage accuracy could be better; no modular
power cables or PCI-E support.
$110, www.coolermaster.com
8
MAXIMUMPC
VERDICT
Vantec Stealth VAN-520A
Proof that sometimes you just can’t make lemons
into lemonade
Back in 2003, we reviewed Vantec’s Ion, an admirably quiet 400-watt
unit which was the company’s first entry in the power supply market.
We liked the Ion, so we had high hopes for the beefy 520-watt Stealth
VAN-520A, which claims to be even quieter than the Ion while providing
more power. Sadly, while the Stealth is indeed quiet, it proved incapable
of delivering even a fraction of its power rating.
The VAN-520A repeatedly crashed our test system during the load
test, while drawing between 365 and 378 watts from the outlet. We tried
rewiring our test system for a different distribution of power, but the
problem remained. We even ran 3DMark03 by itself, and the system still
crashed within minutes.
Even if the Stealth was operating at 75 percent efficiency—which it
wasn’t—it couldn’t have been supplying more than 284 watts when it
crashed (378 watts drawn from the outlet multiplied by an efficiency
factor of 0.75 equals roughly 284 watts of output). That’s a full 236 watts
below Vantec’s claimed capacity, so the VAN-520A’s failure is absolutely
unacceptable. And though the 12.32V output voltage we measured on
the Stealth’s 12V rail is within the limits of the ATX spec, it’s among the
least accurate readings in this roundup.
In an unanticipated slice of real-world testing, we discovered that
the room we conducted our load tests in has faulty electrical wiring
that can’t handle large power draws. Because badly designed PSUs
can place more strain on the wiring in your home, this inadvertently
exposed the Stealth as the most abusive participant in our roundup.
Aside from our 400-watt generic reference point, the VAN-520A was the
only PSU that repeatedly tripped the circuit breaker during our trials.
Feature-wise, the Stealth comes equipped with support for PCI
Express but not Serial ATA. The power cables aren’t modular, but they
are loosely braided for an air of professionalism. The VAN-520A was the
only power supply reviewed
here to offer manual fan speed
adjustments, though even on
its lowest setting, it was no
quieter than the Antec
NeoPower. To play it safe, we
set the fan speed to “auto”
during our tests.
All things considered, we
suggest avoiding this PSU like
the plague.
Quiet, and didn’t blow up during testing.
PATRIOTISM
JINGOISM
Failed load test; lackluster voltage accuracy; no
modular cables, SATA support, or active PFC.
$100, www.vantecusa.com
3
MAXIMUMPC
VERDICT