Enermax Platimax 600W

A Platinum-efficiency (92%) power supply from Enermax, one of the oldest names in the computer power sector, promises superb performance and ultra low noise, like its earlier brethren, Modu/Pro 87+… at a price.

Super high efficiency is the defining mark of high end power supplies, and
the Platimax 600W from Enermax falls easily into that category with its 80 PLUS
Platinum tag. Judging by its published specifications, retail packaging, or
its selling price, there’s no question that this PSU is aimed clearly at the
high end. Enermax does have panache as the earliest retail package PSU brand,
going back some 20 years. It was, for a while, the only retail high end PSU
option, and no doubt I am not alone in recalling the blue metallic painted casings
that marked dual-fan Enermax PSU apart from the generic battleship gray of the
rest. More recently, Enermax 82+ and 87+ Modu/Pro models have fared very well
in SPCR reviews.

But the retail package PSU sector is awash in products with dozens of brands
not long associated with power supplies. Apparently, despite the glut of products,
there is still margin and money to be made here and no shortage of OEM PSU makers
willing to supply any brand, so it has become a popular sector for component
brands to expand into. Enermax is up against lots of competition these days.

There are seven other models in the Platimax series, one lower at 500W, and
the others at 750W, 850W, 1000W, 1250W, 1350W and 1500W. That’s an incredibly
large number of models, especially when some of them are only 100W apart, and
the Platimax is only one of nine series of Enermax PSUs, which
add up to a total of 46 models altogether (by a quick count of
current models on their web site)! I suppose they’re just trying to cover every
niche in the PSU market, but a model at every possible power rating seems like
overkill. How in the world could a retailer possibly stock all of these? And
therein lies the possible answer: They’re not meant to, so retailers don’t compete
directly with the same model? Just a conjecture.

Not many Platinum efficiency PSUs are out there. All the other 80 PLUS Platinum
certified PSUs reviewed by SPCR thus far have come from Kingwin, including a
fan-cooled 550W and the passively cooled 500W STR-500. Many of the major brands
have Platinum PSUs in their lineups, but not all, and both retain inventory
and samples seems hard to come by. Gold level 90% efficiency seems to be almost
ubiquitous now, and perhaps the market is perceived to be too reluctant to bear
the still higher cost of Platinum models, which are only marginally more efficient.
Interestingly, Newegg’s asking price (at time of writing) for the Kingwin LZP-550
(Platinum) is $150, while the Enermax Platimax 600W is $190. That’s a huge difference
for 50W. Notably, the next lower priced 600W PSU at Newegg is an 80 PLUS Bronze
model at $120. 80 PLUS Gold PSUs of 550~650W ratings abound at the $100~$120
range, with brands like FSP, Rosewill, SPI, Seasonic, Cougar, Raidmax, Xclio
and Lepa.

Given the Platimax 600W’s lofty positioning, let’s take a close look at what
is offered.

It’s a sizable, attractive package. More similar colored cardboard insets surround the PSU inside. Beneath it all: The output cables, a couple attached, most modular; a puch for the detachable cables; zip ties and other cable handling accessories; screw; user’s guide; AC cable; the PSU itself.

Overall, while it is nice and complete enough, the package is not much different
from other high end offerings. Perhaps the value is all inside and in the performance.

DETAILS

The Platimax 600W is nicely finished with a tough-looking speckled paint. A
140mm fan with translucent blades is employed behind a wire grill intake, and
the exhaust vent is a typical hex pattern grill. A silver colored inset surrounds
the fan grill; this appears to be primary decorative.

INSIDE THE PLATIMAX 600W

The casing is a classic clamshell design made of sturdy steel sheeting, with
very good fit and finish. The unit is unusual in that it sports three transformers,
and the parts density is high, with at least six daughter boards on the main
PCB. As with so many new high efficiency PSUs, the lower voltage lines are all
derived from the 12VDC line using DC/DC converters.

The twister bearing fan inside is marked as an Enermax, model ED142512W-DA.
This fan was also used in some of the Modu/Pro 87+ PSUs, but repeated searches
of the Enermax site (as well as the web) failed to turn up any specifications
or other information about it. All we have is what Enermax says about the fan
in its PSU description:

• Minimal contact area for effective noise reduction
• Rotor with integrated magnet for frictionless and smooth motion
• Self-lubricating bearing material abrasion protection for longer lifetime

OUTPUT CABLES

The output cables are all nicely sleeved and long enough for most cases with
bottom PSU placement, which puts the main ATX and AUX12V connectors on the motherboard
farther away.

Attached:
1 – Main ATX 20/24-pin connector, 55cm
1 – 4/8-pin + 8-pin AUX12V connectors, 60cm

Modular:
2 – 2x 6+2-pin connectors for video card, 50cm
1 – 4x SATA power connectors, 90cm
1 – 2x SATA + 2x 4-pin Molex power connectors, 90cm
1 – 4x 4-pin Molex and 2x floppy drive power connectors 105cm

TESTING

For a fuller understanding of ATX power supplies, please read
the reference article Power
Supply Fundamentals. Those who seek source materials
can find Intel’s various PSU design guides at Form
Factors.

SPCR’s
PSU Test Platform V4.1. is the basic setup for the testing. It is a close simulation of
a moderate airflow mid-tower PC optimized for low noise. There is one major change: The primary testing is done with the PSU NOT inside the hotbox but atop it, out of the heat path. This is in recognition of several realities that prevail today:

• In SPCR’s earlier test platforms, the internal temperature varied proportionately
  with output load. The tested PSU was subject to this heat, and operating ambient
  temperature rose with increased load, reaching >40°C and often much
  higher at full power. This was a realistic simulation of a mid-tower PC case
  where the PSU is mounted conventionally at the top back portion of the case.
• The vast majority of "serious" PC cases for the home builder place no longer position the PSU at the top back corner. They put the PSU at the bottom/back corner, mostly out of the path of heat from the other components in the case. This design concept took root with the Antec P180 going back over 5 years, and dominates the DIY case arena. This means the PSU generally has to dissipate only its own heat.

Now, we’ve reversed our approach: The PSU is tested briefly in
the hotbox only to check what happens to noise, fan speed and temperatures when
it is used in an outmoded case design.

Acoustic measurements are performed in our own anechoic chamber with ambient level of 11 dBA or lower, with a PC-based spectrum analyzer comprised of SpectraPLUS software with ACO Pacific microphone and M-Audio digital audio interfaces.

REAL SYSTEM POWER NEEDS: While we test the PSU to full
output in order to verify the manufacturer’s claims, real desktop PCs simply
do not require anywhere near this level of power. The most pertinent range of
DC output power is between about 40W and 300W, because it is the power range
where most systems will be working most of the time. It is true that very elaborate
systems with the most power hungry dual video cards today might draw as much
as another 150~300W, but the total usually remains under 600W.

TEST RESULTS

The ambient temperature was ~23°, and the ambient noise level
was ~10 dBA.

1. EFFICIENCY — This is a measure of AC-to-DC
conversion efficiency. The ATX12V Power Supply Design Guide recommends 80% efficiency
or better at all output power loads. 80% efficiency means that to deliver 80W
DC output, a PSU draws 100W AC input, and 20W is lost as heat within the PSU.
Higher efficiency is preferred for reduced energy consumption and cooler operation.
It allows reduced cooling airflow, which translates to lower noise. The 80 Plus
Platinum standard requires 90% efficiency at 20% load, 92% efficiency at 50%
of rated load, and 89% efficiency at full rated load.

At the super low 20W load, efficiency was not bad at 68%. Efficiency
rose fairly quickly as the load was increased. 91% efficiency was reached around
the 150W mark, so the unit probably reaches 90% at 20% of rated load —
120W — as required by 80 PLUS Platinum. It reached almost 94% efficiency
at 200W, and stayed at around that efficiency level till over 300W. The slide
from peak efficiency reached 91% at400W, and it just managed the maximum load
efficiency of 89% (0.1% is too close to callit a miss). So at mid power, the
unit exceeds *0 Plus requirements but just hits the mark at 20% and 100% of
rated load.

There was no issue with crossloading. With virtually the entire
500W load on 12V, naturally, efficiency improved from the standard loading.

2. VOLTAGE REGULATION refers to how stable the output voltages
are under various load conditions. The ATX12V Power Supply Design Guide calls
for the +12, +5V and +3.3V lines to be maintained within ±5%.

The critical 12V line started high at very load load, +0.35V (2.9%).
It dropped gradually as load was increased, reaching a low of 12.2V at full
power. The 5V line started a touch high at 5.08V (+1.5%) and went down to 4.96V
(-0.8%) at full load. 3.3V ranged from 3.38V to 3.29V (+2.4% to -0.3%). These
are excellent results, better than voltage regulation needs to be for any PC.

3. AC RIPPLE refers to unwanted "noise"
artifacts in the DC output of a switching power supply. It’s usually very high
in frequency (in the order of 100s of kHz). The peak-to-peak value is measured.
The ATX12V Guide allows up to 120mV (peak-to-peak) of AC ripple on the +12V
line and 50mV on the +5V and +3.3V lines. Ripple on all the lines was excellent
at all power levels, generally staying under 16mV through the lower half of
the power range. Even at maximum power, the 12V ripple stayed at just 25mV.
It’s about best we have measured.

4. POWER FACTOR is ideal when it measures 1.0. In the most
practical sense, PF is a measure of how "difficult" it is for the
electric utility to deliver the AC power into your power supply. High PF reduces
the AC current draw, which reduces stress on the electric wiring in your home
(and elsewhere up the line). It also means you can do with a smaller, cheaper
UPS backup; they are priced according to their VA (volt-ampere) rating. Power
factor was very goodfor this model, running at or close to 1.0 (not never quite
reaching it) through most of the loads.

5. LOW LOAD TESTING revealed no problems starting at very
low loads. Our sample had no issue starting up with no load, either, and the
power draw was low. The 0.4W power draw in standby (power switch on but computer
off) is excellent.

6. LOW & 240 VAC PERFORMANCE

The power supply was set to 500W load at va rious AC input voltages.
Most full-range input power supplies achieve 2~3% higher efficiency with 220~240
VAC, compared to 110~120 VAC. SPCR’s lab is equipped with a 240 VAC line, which
is used to check power supply efficiency for the benefit of those who live in
higher mains voltage regions. We also used a hefty variac to check the stability
of the PSU under brownout conditions where the AC line voltage drops from the
120V norm.

Efficiency improved to over 94% at 240VAC. The sample passed
the 100VAC minimum input at 500W load without any issues, with a 1.2% drop in
efficiency. Neither voltage regulation nor ripple changed appreciably during
these tests.

7. COOLING & NOISE

The 14cm fan in the Platimax 600W started up at an extremely low
speed, shown by a calibrated strobe to be ~325 RPM. The subjective noise was
inaudible from a meter distance. Very close up (under 1′), a faint constant
noise from the fan was audible, with no apparent electronic buzzing or hum.
On the spectrum analyzer, the overall SPL was ~10 dBA, but it could have been
lower because this is the residual noise level of the anechoic chamber. Turning
the PSU on made no change in the measured noise or spectrum screen with the
microphone a meter away from the PSU. To make the meter register any change
when the PSu was turned on, it had to be brought to a foot distance, at which
point, a broadband rise of about a decibel was seen. This is as quiet as you
can get without removing or stopping the fan altogether.

The noise level did not change till around 400W load, when perhaps
a single dBA increase, to 12 dBA@1m, was seen. It was still effectively inaudible.
After about 5 minutes at 500W load, the fan finally sped up to perhaps 800 RPM,
and the SPL stabilized around 18 dBA@1m. Amazingly, even after 10 minutes at
full power (600W), the measured SPL was still only 24 dBA@1m.

With such low fan speeds, the exhaust temperature was perhaps
a touch higher than with other PSUs at low loads, but the difference was irrelevant
as it was still well under 30°C. Even at quite high load, 400W, when the fan
started spinning up a bit, the exhaust temperature was only 32°C. The 34°C seen
at 600W is low. The self-cooling ability of this Enermax is pretty amazing.

IN THE HOT BOX

When exposed to the heat of the hotbox, the Platimax 600W fan
started to spin up about 100W lower, but the overall noise profile really changed
very little. Even in an old-style case with poor fresh air intake for the PSU,
the Platimax 600W will remain very quiet to over 400W load. This is exceptional
performance.

COMPARISONS

The comparison table below shows the SPL versus Power Load data on PSUs tested
in ambient room temperature, typically 20~24°C. It is most relevant when PSUs
are used in cases that provide wide open access to cooler outside air for the
PSU cooling fan. The Platimax 600W achieves the same silent performance as its
brethren Modu/Pro87+ 500. At 600W load, it is as quiet as the best on the entire
list.

The comparison table below shows the SPL versus Power Load data on all the
PSUs tested in the hotbox. It’s difficult to rank them, as the measured SPL
varies with power load. The units which are quietest at minimum load are not
always the quietest at midload (100W~300W), which may make them louder in actual
use. Then there’s the noise level at 400W and up, which will determine the quietest
PSUs for high power gaming rigs, during actual gaming. In this environment,
the Platimax 600W essentially matches the Kingwin Platinum 550W but edges it
because it has 50W higher output.

Caution: Please keep in mind that
the data in the above table is specific to the conditions of our test setup.
Change the cooling configuration, the ambient temperature and any number of
other factors, and you could change the point at which the fans start speeding
up, as well as the rate of the rise in speed. The baseline SPL is accurate,
however, probably to within 1 dBA.

CONCLUSIONS

The Enermax Platimax 600W power supply delivers all the
performance it promises, with exceptionally low noise at every power level under
cool or hot conditions. Its electrical performance is excellent, and its acoustics
are better than any other 600W PSU, and certainly a match in actual use for
any fanless PSUs as well (and usually more pratical and easier to deploy).

There is really nothing negative to say about the Platimax 600W.
One could quibble that its efficiency could be better at very low loads, but
the counter argument is that if that is important, you should be looking at
a lower rated PSU, as no PSU cannot be expected to be as efficient at 5% of
rated load as at 50%. You could also complain that the 12V rail could be closer
to 12V, rather than 0.35V high, or that the 5V regulation could better, especially
at higher load. You could ask why the 12V rail is divided up into three 25A-limited
lines when this is no longer required. Overall, however, the single substantial
complaint you could make is that the Platmax 600W is overpriced.

A Platinum efficiency 600W Sparkle PSU is list at Newegg for $110.
This is the lowest priced Platinum at the 550W~650W power range; there are about
several other price around the $110~130 range. We cannot assume without a close
examination that these other competitors match all of the Platimax 600W’s laudable
traits, but its $190 price tag at the same store has to be questioned. Is the
Platimax better enough to justify this kind of price premium?

The Platmax 600W is a super-quiet, high performance, very high
efficiency PSU with modular cables and a 5-year warranty. This is enough to
earn an Editor’s Choice award… but I’d hold out for a better price before
buying.

Much thanks to Enermax
USA for the review sample.

Enermax Platmax 600W receives the SPCR Editor’s Choice Award

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SPCR Articles of Related Interest:
Power Supply Fundamentals

Recommended Power Supplies
SPCR PSU Test Rig
Kingwin
Stryker STR-500
Seasonic G360
Enermax Modu87+ 500W 80Plus Gold

Seasonic X-650: Seasonic Hits
Gold
Kingwin Lazer Platinum
550W Power Supply

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