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Seasonic Goes Green: The Eco Power 300

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Green has quickly become a veritable marketing cliche. What does it mean in the context of electronics? Most manufacturers say efficiency, RoHS compliance, and recycling friendliness. Seasonic’s Eco Power 300 adds green packaging and sensible power sizing while retaining the brand’s traditional strengths in efficiency and acoustics in a very small package.

Jan 2, 2008 by Devon Cooke

Product
Seasonic Eco Power 300
300W SFX12V 80-Plus Power Supply
(Also compatible with ATX12V 2.01)
Manufacturer
Seasonic
MSRP
US$65

Green tech has taken off. In recent months, SPCR has reviewed a
Green drive
, a Green monitor,
a Green laptop, and more
than one
Green power supply.
We also launched our sister site, Eco
PC Review
, which focusses specifically on Green computing. Despite all this
attention, few of these so-called Green products have done more than tweak power
consumption and rewrite the product’s PR to tout its Greenness. But, as our sister site Eco PC Review discovered, there is far more to environmentally-friendly
computing than knocking the power consumption down by a couple watts.

As it stands today, it would be a stretch to call even a solar-powered laptop
Green because the vast majority of a laptop’s energy footprint is expended in
the manufacturing process, not everyday operation. The same applies to just
about every piece of consumer electronics on the market. Europe’s
RoHS initiative
, which, among other things, banned the use of lead in electronics,
will arguably do much more for the environment than the
far-better publicized 80-Plus program
. In fact, insofar as the 80-Plus program
stimulates the sale of new power supplies as replacements for older, working
power supplies, it is responsible for a certain amount of environmental damage
itself.

Barring a major change in the way electronics are manufactured, we’re never
going to see a truly Green power supply, but that doesn’t mean some manufacturers
aren’t making an effort to clean up their acts. The latest to the market is
Seasonic with the Eco Power 300. Seasonic has a long history of building highly
efficient power supplies, so they will need to do something special to set the
Eco Power apart from their regular models.


Simple, unbleached cardboard packaging.

The Eco Power starts with RoHS compliance (required) and 80-Plus certification
(standard for Seasonic), but this is the bare minimum we’d expect of an ecologically-friendly
power supply. For that matter, we expect these features of just about any power
supply, not just Green ones.

The most obviously Green feature is apparent without even opening the box because
it is the box itself. In contrast to the usual brightly colored retail packaging,
the Eco Power comes in a plainish brown cardboard carton printed with monochrome
black ink in a style reminiscent of Thermalright’s
packaging
. The only splash of color is a label that advertises a five year
warranty. Seasonic’s words on the matter do a good job of highlighting how far
the electronics industry has to go: "Innovative use of 100% recycled cardboard
has eliminated all packaging plastics, placing Eco Power 300 at the forefront
of green electronic design." Cardboard packaging seems indeed to
be the forefront of green electronic design, so clearly there is work to be done!

Nevertheless, every little bit helps, and we’re not about to knock their effort.
Recycled cardboard is widely available, though it can be difficult to verify
just how much post-consumer waste is actually present. Seasonic also notes that
the ink is non-toxic, though it’s not clear whether this also means environmentally-friendly.
We were almost able to verify the lack of plastic — there was no sign of
the usual plastic bags or bubble wrap around the power supply; however, a pair
of small ziplock baggie containing the mounting screws proved that ditching
plastic entirely is harder than it seems. (Come to think of it, "ditching
plastic" seems like an unfortunate choice of words — we’d rather keep
the plastic out of the ditch entirely.)


Things stay simple and unbleached inside as well…


…with no sign of the usual plastic padding.

The contents of the package are fairly minimal, though not quite bare-PSU-minimal.
A small, single-sheet warranty card is included, plus "extras" including
an AC power cable and adapters for floppy and PCIe connectors, as well as mounting
screws and an SFX to ATX adapter plate that allows the oddly-shaped SFX-power
supply to be installed in standard ATX cases. With the exception of the warranty
card and the PCIe adapter (high power graphics cards have no place in a Green
PC), all of these are necessary for regular operation of the power supply. The
PCIe adapter is probably a compromise, given how difficult it is to sell a power
supply without one.


Several adapters for wide compatibility.

FEATURE HIGHLIGHTS

Seasonic Eco Power 300 Feature Highlights (from
Seasonic web site)
FEATURE & BRIEF COMMENT
Universal Video Card Support
Support new PCI-E video card technologies
Compatibility is nice,
though power-guzzling PCIe graphics cards aren’t exactly Green.
Smart & Silent Fan
Control [ S²FC]

Smart thermal control to balance noise & cooling.
The same fan controller
we’ve recommended for years.
Super High Efficiency [up to 85%]
Optimal solution for low energy consumption, noise & heat.
Low power consumption
is certainly Green, though efficiency is less important than the consumption
of the overall system.
Active Power Factor
Correction [99% PF]

Reduces line loss & power distortion.
Reduced line losses benefit
the utility company and mean less power has to be generated at the power
station.
Double Ball Bearing Fan
Increases airflow & lifetime and reduces rotation speed and noise.
The safe choice for a
high heat environment like a power supply.
Universal AC Input [Full
Range]

Plug & run safely anywhere in the world.
A small environmental
benefit in that less overstock is likely to be produced when there is a
single international model.
5 Year Warranty
Our Commitments to superior quality.
Pretty good if you like
warranties.

SPECIFICATIONS

OUTPUT SPECIFICATIONS: Seasonic Eco Power 300
AC Input
100-240Vac; ~5A; 50/60 Hz
DC Output
+3.3V
+5V
+12V1
+12V2
-12V
+5VSB
Maximum
Output Current
20A
20A
8A
14.5A
0.8A
2.0A
125W (28A) 270W
Maximum
Combined Power
300W
Operating temperature: 0 to 50°C. Relative Humidity:
20% to 80%.
(The rated power will reduce from 100% to 80% from 40°C to 50°C)

EXTERNAL TOUR

The Eco Power conforms to the SFX12V form factor, so it is about half the size
of a standard ATX12V power supply. A steel adapter plate is included so that
it can be installed in regular ATX systems. Its small size lends credibility
to its Green claims — less volume means less overall materials went into
its construction, which in turns means a smaller environmental footprint.

A close look at the label reveals that Seasonic’s internal model number is
SS-300SFD — the same model
that we tested with an efficiency above 85%
. The differences between that
unit and the Eco Power 300 are minimal; it’s most likely only the extras included
in the retail package that set them apart.


Smaller physical footprint = smaller environmental footprint.


An ATX adapter plate allows the Eco Power to be installed in standard cases.


The casing is unpainted steel.


This restrictive grill is typical of SFX12V power supplies. What does that
mean for airflow?

 

CABLES AND CONNECTORS

There are five cable sets and two adapters, all of which are quite short. Regular
ATX-style cases should be alright, but don’t expect to do much in the way of
fancy cabling. The limited set of connectors is enough for a simple system,
but it’s not really intended for use in high end or gaming rigs.

  • 12″ cable for main 20+4-pin ATX connector
  • 13″ cable for 4-pin AUX12V connector
  • 1 x 25″ cable with three 4-pin IDE drive connectors
  • 1 x 19″ cable with two 4-pin IDE drive connectors
  • 1 x 16″ cable with two SATA drive connectors
  • 1 x 4" adapter from two 4-pin IDE connectors to one PCIe graphics connector
  • 1 x 6" splitter from one 4-pin IDE connector to two floppy connectors

INTERIOR

The internal components in the Eco Power 300 are densely packed, with little
room for airflow between them. On the whole, components are smaller and fewer
than in the high capacity gaming power supplies that we usually see. In part,
this is due to the necessity of jamming everything within the confines of an
SFX12V enclosure, but it is also because a 300W power supply doesn’t require
as hefty components.

Once again, this is a good thing for the environment. Higher capacity power
supplies require bigger and higher grade electronics, which have a corresponding
environmental cost, either because more toxic materials are required or heavier
refinement is needed to meet higher tolerances. Our
extensive research that shows that the vast majority of systems will fit within
a 300W power envelope
, so the Eco Power 300 should have no difficulty delivering
the goods while still using fewer raw materials than typical "high end"
500W+ units.


Densely packed electronics.


For the most part, the electronic components are smaller than usual.


Fancy three-layer heatsinking.

FAN

As is usual for Seasonic’s power supplies, the fan is made by Adda, in this
case, an 80mm ball-bearing model. The fan is a high speed model, and is unlikely
to be quiet at full speed. Whether it is quiet at lower speeds remains to be
seen.


High speed and ball bearing … not good for noise.

TESTING

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

For a complete rundown of testing equipment and procedures,
please refer to SPCR’s PSU Test Platform V.4.
The testing system is a close simulation of a moderate airflow
mid-tower PC optimized for low noise.

In the test rig, the ambient temperature of the PSU varies
proportionately with its output load, which is exactly the way it is in
a real PC environment. But there is the added benefit of a high power
load tester which allows incremental load testing all the way to full
power for any non-industrial PC power supply. Both fan noise and
voltage are measured at various standard loads. It is, in general, a
very demanding test, as the operating ambient temperature of the PSU
often reaches >40°C at full power. This is
impossible to achieve with an open test bench setup.

The 120mm fan responsible for “case airflow” is deliberately
run at a steady low level (~6-7V) when the system is run at “low”
loads. When the test loads become greater, the 120mm fan is turned up
to a higher speed, but one that doesn’t affect the noise level of the
overall system. Anyone who is running a system that draws 400W or more
would definitely want more than 20CFM of airflow through their case,
and at this point, the noise level of the exhaust fan is typically not
the greatest concern.

Great effort has been made to devise as realistic
an operating environment for the PSU as possible, but the thermal and
noise results obtained here still cannot be considered absolute. There
are too many variables in PCs and too many possible combinations of
components for any single test environment to provide infallible
results. And there is always the bugaboo of sample variance. These
results are akin to a resume, a few detailed photographs, and some
short sound bites of someone you’ve never met. You’ll probably get a
pretty good overall representation, but it is not quite the same as an
extended meeting in person.

SPCR’s
high fidelity sound recording system
was used to
create MP3 sound files of this PSU. As with the setup for recording
fans, the position of the mic was 3″ from the exhaust vent at a 45°
angle, outside the airflow turbulence area. The photo below shows the
setup (a different PSU is being recorded). All other noise sources in
the room were turned off while making the sound recordings.

INTERPRETING TEMPERATURE DATA

It important to keep in mind that fan speed varies with temperature,
not output load. A power supply generates more heat as output
increases, but is not the only the only factor that affects fan speed.
Ambient temperature and case airflow have almost as much effect. Our
test rig represents a challenging thermal situation for a power supply:
A large portion of the heat generated inside the case must be exhausted
through the power supply, which causes a corresponding increase in fan
speed.

When examining thermal data, the most important indicator of
cooling efficiency is the difference
between intake and exhaust. Because the heat generated in the PSU
loader by the output of the PSU is always the same for a given power
level, the intake temperature should be roughly the same between
different tests. The only external variable is the ambient room
temperature. The temperature of the exhaust air from the PSU is
affected by several factors:

  • Intake temperature (determined by ambient temperature and
    power output level)
  • Efficiency of the PSU (how much heat it generates while
    producing the required output)
  • The effectiveness of the PSU’s cooling system, which is
    comprised of:
    • Overall mechanical and airflow design
    • Size, shape and overall surface area of heatsinks
    • Fan(s) and fan speed control circuit

The thermal rise in the
power supply is really the only indicator we have about all of the
above. This is why the intake temperature is important: It represents
the ambient temperature around the power supply itself. Subtracting the
intake temperature from the exhaust temperature gives a reasonable
gauge of the effectiveness of the power supply’s cooling system. This
is the only temperature number that is comparable between different
reviews, as it is unaffected by the ambient temperature.

NOTE: Because of the Eco Power 300’s unusual shape and size,
it was difficult to position in our PSU thermal load tester. We used various
pieces of foam to block off spaces not covered by the PSU.

TEST RESULTS

Ambient conditions during testing were 21°C and 21 dBA. AC input was 120V,
60Hz.

OUTPUT, VOLTAGE REGULATION & EFFICIENCY: Seasonic
Eco Power 300











DC Output Voltage (V) + Current (A)

Total DC Output

AC Input

Calculated Efficiency
+12V1
+12V2
+5V
+3.3V
-12V
+5VSB
12.09
0.96
12.09
5.01
0.98
3.30
0.93
0.1
0.1
21.3
31.3
68.0%
12.08
12.07
1.70
5.01
0.97
3.30
0.92
0.1
0.2
30.6
41.5
73.8%
12.12
12.11
1.70
4.99
1.92
3.29
1.83
0.1
0.3
38.9
51.6
75.4%
12.06
1.86
12.05
1.71
5.00
1.92
3.28
2.60
0.2
0.4
65.6
80.8
81.1%
12.06
2.82
12.06
1.71
4.99
3.56
3.30
3.56
0.2
0.6
89.5
108.7
82.4%
12.05
4.68
12.05
3.25
4.96
5.31
3.27
5.06
0.4
1.0
148.2
179.7
82.5%
12.04
5.59
12.01
4.93
4.94
7.13
3.25
8.11
0.5
1.3
200.6
239
83.9%
12.06
8.54
12.04
4.94
4.94
8.88
3.24
8.17
0.7
1.7
249.7
303
82.4%
12.06
9.38
12.01
6.36
4.93
11.04
3.24
11.13
0.8
2.0
299.6
372
80.5%
Crossload Test*
11.60
14.61
11.59
7.73
5.13
0.99
3.27
0.91
0.0
0.0
267.1
328
81.4%
+12V Ripple (peak-to-peak): 28mV @ no load
+5V Ripple (peak-to-peak): 32mV @ no load & max
+3.3V Ripple (peak-to-peak): 32mV @ no load & max
*For the crossload test, the 12V line is maximized,
and the +5V and +3.3V lines are set to just 1A.

NOTE:
The current and voltage for -12V and +5VSB lines is not measured
but based on switch settings of the DBS-2100 PS Loader. It is a tiny portion
of the total, and potential errors arising from inaccuracies on these
lines is <1W.
OTHER DATA SUMMARY: Seasonic Eco Power 300
DC Output (W)
21.3
30.6
38.9
65.6
89.5
148.2
200.6
249.7
299.6
Intake Temp (°C)
21
22
21
23
25
29
31
31
30
Exhaust Temp (°C)
25
27
28
31
34
38
38
40
41
Temp Rise (°C)
4
5
7
8
9
9
7
9
11
Fan Voltage (V)
4.1
4.1
4.1
4.1
4.1
5.8
7.4
11.1
11.1
SPL (dBA@1m)
23
23
23
23
23
27
33
40
40
Power Factor
0.97
0.98
0.99
1.00
0.99
1.00
0.99
0.99
0.99

AC Power in Standby: 0.9W / 0.24 PF
AC Power with No Load, PSU power On: 6.5W / 0.75 PF
NOTE: The ambient room temperature during
testing can vary a few degrees from review to review. Please take this
into account when comparing PSU test data.

ANALYSIS

1. EFFICIENCY

Efficiency was excellent across the board, though not quite as high as the
predecessor sample we tested
. It also missed the marks set by some other
unusual power supplies, such as Sparkle’s
SPI220LE
and the picoPSU.
In any case, it exceeded the minimum 80% efficiency required by 80-Plus at
each of the 20%, 50%, and 100% load marks.

Low-end Efficiency Comparison
Power Level
~20W
~40W
~65W
~90W
picoPSU + 120W brick
77.7%
85.6%
87.1%
87.1%
Seasonic SS-300SFD
81.5%
83.6%
84.6%
Sparkle SPI220LE
73.0%
80.5%
82.8%
83.8%
Seasonic Eco Power 300
68.0%
75.4%
81.1%
82.4%

In this matchup of the truly high efficiency power supplies, the Eco Power
comes off looking somewhat ordinary, but rest assured that it’s not. The comparison
is designed to exaggerate the differences between the various power supplies.
In all cases, the difference between the most efficient picoPSU and the Eco
Power is less than 5W — hardly enough to save the world. And, given that
most power supplies (especially high capacity units) struggle around 50% efficiency
at 20W, the Eco Power’s 68% performance isn’t too shabby.

Overall, the efficiency curve is fairly flat, and quite high through most of its range. The peak was just shy of 84%, reached at 200W,
but most environmentally conscious users will never push it this high; a basic
midrange system should float somewhere between 50~100W under most conditions.

2. VOLTAGE REGULATION was excellent, with all voltages dropping slightly
as the load increased. Voltages did not sag significantly at full load, indicating
that the unit was fully capable of delivering its rated capacity safely. The
most significant voltage drop we saw was during the crossload test, when both
12V lines dropped to ~11.6V, but even this is well within the 5% range required.

3. RIPPLE

Ripple was well within specifications, especially on the all-important 12V
line. Peak ripple was observed under both full-load and no-load conditions,
but typical ripple was generally about half the peak measured.

4. POWER FACTOR was close to perfect across all loads, as is the norm
for most power supplies with active correction circuitry. It remained excellent
even at the ultra-low 20W load.

5. LOW LOAD PERFORMANCE

The Eco Power had no issues starting with no load or very small loads. Its
power consumption in standby was a little higher than we are used to seeing,
but at 0.9W it was still barely a trickle.

6. TEMPERATURE & COOLING

Cooling was pretty good for such a small, packed unit, but that’s more a
testament of the unit’s high efficiency and low capacity than anything else.
Seasonic’s multi-layered heatsinks may also play a role. The internal temperature
rise remained safely below 10°C through all but the full load test. We
have no worries about the Eco Power’s resilience under load.

7. FAN, FAN CONTROLLER and NOISE

The noise characteristics of the Eco Power weren’t really on par with what
we expect from Seasonic. In part this is due to the smaller fan and the tight
confines of the SFX12V form factor. However, the baseline noise level turned
out to be 1 dBA@1m higher than the older SS-300SFD that we tested, so we know
Seasonic can to better. The increase in noise is most likely caused by the
higher minimum fan voltage in the Eco Power, though the switch to a ball-bearing
fan may also have made a difference. A fan swap could certainly help things
here.

Subjectively, the noise character wasn’t especially smooth, but it was broadband
without pure tones. We’ve certainly heard better (in the Seasonic-made, Antec-branded
NeoHE for example) from an 80mm fan, but we’ve also heard much, much worse.

The fan controller was a regression compared to the one found in Seasonic’s
ATX models. The noise level rose significantly at ~150W, and anything above
this load quickly became load. Users who want to avoid hearing the
fan ramp up and down would be advised to keep their systems under 150W peak demand.

MP3 SOUND RECORDINGS

Each of these recording start with 6~10 seconds of silence to
let you hear the ambient sound of the room, followed by 10 seconds of
the product’s noise.

  • Seasonic Eco Power 300 at 20~90W output, 23 dBA@1m: One meter
  • Seasonic Eco Power 300 at 150W output, 27 dBA@1m: One meter

Sound Recordings of PSU Comparatives

  • Seasonic S12II-380 at up to ~200W output, 21 dBA@1m: One
    meter
  • Sparkle Power SPI220LE at 65W output, 21 dBA@1m: One meter

HOW TO LISTEN &
COMPARE

These
recordings were made with a high resolution, studio quality, digital
recording system, then converted to LAME 128kbps encoded MP3s. We’ve
listened long and hard to ensure there is no audible degradation from
the original WAV files to these MP3s. They represent a quick snapshot
of what we heard during the review. Two recordings of each noise level
were made, one from a distance of one meter,
and another from one foot away.

The
one meter recording is intended to give you an idea of how the subject
of this review sound in actual use — one meter is a reasonable typical
distance between a computer or computer component and your ear. The
recording contains stretches of ambient noise that you can use to judge
the relative loudness of the subject. For best results, set your volume
control so that the ambient noise is just barely audible. Be aware that
very quiet subjects may not be audible — if we couldn’t hear it from
one meter, chances are we couldn’t record it either!

The
one foot recording is designed to bring out the fine details of the
noise. Use this recording with caution! Although more detailed, it may
not represent how the subject sounds in actual use. It is best to
listen to this recording after you have listened to the one meter
recording.

More
details about how we make these recordings can be found in our short
article: Audio
Recording Methods Revised
.

CONCLUSIONS

Seasonic’s marketing material does a good job of summing up what’s good and
what’s bad about the Eco Power 300: "Innovative use of 100% recycled cardboard
has eliminated all packaging plastics, placing Eco Power 300 at the forefront
of green electronic design." On the one hand, there’s something to Seasonic’s
claim that the Eco Power is at the forefront of green design. On the other, the main basis of the claim to green is just packaging; no quantum leap in electronic manufacturing efficiency is claimed.

Have pity for Seasonic’s marketing team though: The greenest feature of the
Eco Power 300 is one that doesn’t translate easily into marketing material: Its modest 300W capacity. Not only do smaller power supplies tend to have flatter
efficiency curves and better low-power efficiency, they also require substantially
less material to produce — and that’s the key to Green electronics. The
unusual form factor is also to its advantage here, and they’ve made a wise move
to include an adapter plate for ATX systems.

The reality is, Seasonic hasn’t really produced an outstandingly Green power
supply; they’ve given people a reason to buy a properly-sized power supply rather
than a massively over-powered model. And, if it works, that in itself will probably
do more for the environment than all the efficiency improvements in the world.
Just as the car industry is convincing people to drop their heavy SUVs for efficient
sub-compacts, Seasonic is trying to sell a smaller, more environmentally-friendly power supply. Given that the Eco Power 300 is one of the few good quality 300W
power supplies on the market, we wish Seasonic the best of luck capitalizing
on this developing market segment. We look forward to seeing even smaller units
in the future.

Much thanks to Seasonic
USA
for this review sample.

* * *

SPCR Articles of Related
Interest:
Power Supply Fundamentals
Recommended
Power Supplies


Power
Distribution within Six PCs

SPCR
PSU Test Rig V.4

Sparkle Power SPI220LE 80 Plus FlexATX PSU
Seasonic SS-300SFD 80 Plus: Little Big PSU

* * *

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