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Enermax Galaxy: A KiloWatt power supply

March 18, 2007 by Arthur Armstrong and Mike
Chin

Product
Enermax Galaxy EGA1000EWL-DXX02

EPS12V 2007 compliant 1000W power supply
Manufacturer
Enermax
Sample Supplier
Maxpoint USA
Market Price
US $310 - $340

Please welcome Arthur Armstrong to SPCR's Vancouver, BC editorial / lab team. Arthur is enrolled in the robotics undergraduate program at the BC Institute of Technology, and dreams of working in this field in China one day soon.

- Mike Chin, Editor

It is with some reluctance that we accepted the Enermax Galaxy for review. Let's face it, a 1kW power
supply isn't aimed at a quiet system for your living environment. SPCR remains interested primarily in examining products that have good potential for quiet performance. If sometimes we come across products that don't quite make the grade, that's OK, but a kilowatt PSU does not really have much of a chance. How could it cool itself quietly at even half power? Nonetheless,
the Bonefish edition of our power supply testing platform was constructed
specifically to accommodate this level of power delivery. The reality is that kilowatt power supplies for computers are becoming amazingly visible in the market today.

The perceived need for such high power comes entirely from the computer gaming world. nVidia maintains a list of components that are certified for systems using their SLI dual-video card technology. In mid-March 2007, among the 13 PSU models certified for Dual GeForce 8800 GTX graphics cards systems, there are four rated at 1000W or higher from PC Power & Cooling, Tagan, and Topower. There are no models rated less than 750W in this category.

The need for such power is dubious. The simple fact is that conscientious testing by performance-oriented hardware web sites do not actually show any clear evidence of such high power demand from real systems. In Tech Report's Jan 2007 comparison of several high end graphics cards, their Intel Core 2 Extreme X6800 based, highest power, dual ATI Radeon X1950 XTX Crossfire system pulled only 400W peak AC from the wall. Based on the ~80% efficiency of the PSU used in that system, this translates to 320W in DC power delivery, less than half of the 750W rating of the smallest PSU on the aforementioned nVidia certified list. All indications are that the X1950 XTX remains about the most power hungry of all the graphics cards. So unless you're using four of them in some ungodly setup, these >750W recommendations by nVidia and others are meant to spur those who feel inadequate unless they have more horses under the hood: "My computer has two Uber-X Graphics Cards and a kilowatt power supply!" We think it's silly and wasteful.

But never mind. There have been the odd calls for reviews of kilowatt PSUs by SPCR. Ye ask and ye shall receive. We'll do our best to determine how well the Galaxy meets up to its own expectations and ours.

PACKAGING, ETC.

The box is a typical design showing off power specs on the back and a few other
tidbits intermixed with spiffy art.



Unit may or may not generate ooze.

Upon opening the box, our first impression is one of... bounty, as in bountiful or even excessive. They
have provided an armful of cables sufficient to connect 24 drives from this
single unit! The next most obvious trait is its hefty dimensions. There are some heavyweights, but this one may take the cake.



Super wire carrying case for the off chance you don't use all your connectors

The Galaxy is about 50% longer (or deeper) than specified by the ATX12V form factor. This will
cause problems with a lot of cases. Height and width are within standard range
so it will slide into the case without complaint. At 220mm lengthwise (not including
cables), the case must be substantially longer (or deeper) than the standard tower or midtower to accommodate. Any case that uses only four screws on the back panel to hold the PSU in place is not recommended. This baby needs support beneath it; otherwise, the cantilever force of its weight hanging off the back panel could damage it, especially with any kind of physical shock.

Some effort has gone into the appearance.
The metal case is a stamped black gloss patterned with large Galaxy prints on
either side. Fan grills are made a shiny gold color. On our unit the fan was
clear showing off the innards, although, there is also a version with solid
black fans. A functional LED adorns the back side next to the power switch and
a warning reset button. All the wires are surrounded by a yellow and black mesh.



80mm + 135mm fan: Probably needed at max speed at full power.

FEATURE HIGHLIGHTS

Enermax Galaxy EGA1000EWL-DXX02 Feature Highlights
(from
Enermax's
web site)
FEATURE & BRIEF OUR COMMENT
Quad CPU/CORE Support
You know... In case you
need to run 4 CPUs off of it.
Quad GPU Support If you really really
want 4 Graphics Processing Units running simultaneously the
Quad
GPU
Support can make it happen.
Five +12V Rails
Now here's an interesting
change of pace. Really! There are two sets of electrically isolated
12V transformers instead of the typical single 12V transformer
with common ground. Benefits of the split transformers may include things
like improved cross loading.
Power Guard
Essentially
it'll shut off the system if power levels get too low or high. It also denies
us no load starting, and has a fairly easy to understand system of beeps
and lights to tell you what's gone wrong.

If you are in fact running 4 graphics processor units then there is the unflinching
support. It should be noted, however, that even the most graphics intensive
games will run unhindered on 2 decent GPUs. Maybe this looks forward to a more
graphics intense era? That's plausible.

We were pretty happy with the marketingspeak so far. They hadn't overstepped
themselves in the way a marketing department almost always does. Unfortunately
the rest is coming...

World's FIRST: 80-85% efficiency
from 20% to 100% load.
First? Really? Are you guys exaggerating???
SILENT & COOL by 13.5cm &
8cm dual fan design.
This is a perennial favorite laugh. Especially
among high power PSUs.
World's FIRST: COMBINED MINIMUM LOAD
design for outstanding compatibility.
Hmm... The Power Guard kinda makes this redundant.
World's STRONGEST: 6A +5Vsb
rail to support
2007 systems and multiple USB devices.

It might be relevant for users who use lots of external devices, but not for those who can install 24 peripheral components in the PC.

World's FIRST: RAM POWER CABLE for
32-64GB RAM system support.
That's not really necessary.


SPECIFICATIONS

OUTPUT SPECIFICATIONS: Enermax Galaxy EGA1000EWL-DXX02
AC Input
100-240 VAC, 10/6 A, 60/50 Hz
DC Output
+3.3V
+5V
+12V1
+12V2
+12V3
+12V4
+12V5
-12V
+5VSB
Maximum

Output Current
30A
30A
17A
17A
17A
17A
17A
0.6A
6A
41A
34A
75A
Maximum

Combined Power
250W
812W
7.2W
30W
1000W (1100W)

That added feature of separating 12V lines
into two sets is a nice bonus. The problems that arise from not separating
them may be very small, but it's a feature we can appreciate. Especially since
if you are indeed drawing max amperage on three lines and doing finer work on
another, noise can cause problems. For a more detailed discussion of dual transformers for 12V please see the specs section of the Tagan EasyCon XL 700W article.

CABLES AND CONNECTORS

If you're wondering, "Do they really give the option to power 24 drives???",
yes they did. Here's a photo with as many cables as we could attach plus the unused ones, and the complete list.

Attached cables: There are so many that even without adding a single detachable one, cable management is a bit of mess.

  • 1 x 21" main 20+4 ATX
  • 1 x 21" cable with 6-pin PCIE plug and 6/8-pin PCIE plug
  • 1 x 21" cable with 6/8-pin PCIE plug
  • 1 x 33" fan RPM header
  • 1 x 30" w/ three 4-pin Molex plugs
  • 1 x 30" w/ three SATA plugs
  • 1 x 24" with 4x12V plug + two 2x12V joinable plugs (for CPUs)

Modular cables:

  • 5 x 30" with 3 SATA
  • 3 x 30" with three 4-pin Molex
  • 2 x 30" w/ floppy + two 4-pin Molex
  • 2 x 16" 6-pin PCIE
  • 1 x 16" 2x12V (This is apparently for RAM power.)

Adapter:

  • 1 x 4" 8P CPU to 6/8 PCI-E adapter

EXTERNALS

Note the little red button next to the power button. That's the reset for the Power Guard.



It looks innocuous from the back.



Those vents could end up dumping heat back into the case.

The output cable side has a pretty big opening, a series of slot vents. Its possible that the airflow in the PSU is designed to make those vents act as intakes, to pull air out from the case through the PSU. On the other hand, they could very easily turn into exhaust vents. Unless the 80mm fan is spinning much faster than the 135mm fan, the flow of the latter will far exceed the former. Faced with any bottleneck, air simply finds the path of least resistance, which in this case, could be the slot vents. The downside is that some of the heat of the PSU itself will simply find its way back into the interior of the case/system.

INTERIOR

Impressions are positive. The components are packed in tightly, and the quality of the visible components looks good. All the smaller capacitors jammed in near the coils at the bottom of the photo below are rated 105°C, for example. The main large capacitors, on the other hand, are rated 85°C. Note the two 12V transformers



Despite its large casing, it's fairly well packed.

Under that gray mat to the left is a third smaller transformer.
We speculate the flap is used for better venting since it's also covering part
of the intake. As you can see, long heatsinks line the rectifiers for heat dissipation.
The fins are fairly short, but their number make up for that somewhat.

FANS

As already mentioned, Enermax has chosen a larger
fan than the 12cm standard. This may seem an obvious development, and it is.
A bigger fan moves more air in as many turns. The 13.5 fan is listed in the Globe
Fan
web site and is rated for maximum 1800 RPM, 96 CFM airflow, and 40.4 dBA (presumably at 1m).



This "Silence" brand fan model number shows up in Globe Fan's database.



The 80mm fan is a SuperRed brand by Cheng Home Electronic.

The Super Red brand of fan was used briefly in Seasonic Super Silencer power supplies a couple of years ago. This particular model uses a double ball bearing and is rated for 3600 RPM, 44-46 CFM and 37-39 dBA.

Neither fan will be quiet at full speed, but a good fan controller should be able to keep them pretty quiet.

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.
A complete ssi EPS12V PSU standards can be found on the ssi
forum.

You can find out everything you want to know about SPCR's test equipment at
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.

REAL SYSTEM POWER NEEDS: While our testing loads 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 65W and 250W, because it is the power range where most
systems will be working most of the time. To illustrate this point, we
conducted system tests to measure the maximum power draw that an actual
system
can draw under worst-case conditions.
Our most power-hungry
Intel 670 (P4-3.8) processor rig with nVidia 6800GT video card drew ~214W DC
from the power supply under full load — well within the capabilities of any
modern power supply. Please follow the link provided above to see the details.
It is true that very elaborate systems with the most power hungry video card
today could draw as much as another 60~100W, but the total still remains well
under 400W in extrapolations of our real world measurements. As for high end
dual video card gaming rigs... well, to be realistic, they have no place in
silent computing today.

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.

TEST RESULTS

Opening conditions for this test were measured at 21°C and 20 dBA.
The input voltage was 122VAC.

It took some effort to get this big boy into place, but we came
out with a sense of accomplishment. The connectors
were duly plugged in, and the testing was begun!



Our PSU tester is beginning to look like a Frankenstein creation.

OUTPUT & EFFICIENCY: Enermax Galaxy EGA1000EWL-DXX02











DC Output Voltage (V) + Current (A)

Total DC Output

AC Input

Calculated Efficiency
+12V1
+12V2
+12V3
+5V
+3.3V
-12V
+5VSB
12.15
0.96
12.15
1.70
-
-
5.06
1.01
3.35
1.00
0.1
0.1
40.8
76
53.6%
12.15
1.89
12.12
1.70
-
-
5.06
2.86
3.35
2.71
0.1
0.2
69.3
108
64.5%
12.15
2.83
12.11
3.36
-
-
5.06
1.98
3.35
0.96
0.1
0.4
91.5
140
65.4%
12.13
3.72
12.07
4.93
-
-
5.06
5.57
3.36
5.54
0.1
0.4
154.6
202
76.5%
12.12
5.55
12.06
4.92
-
-
5.05
7.87
3.37
7.61
0.2
0.5
196.9
253
77.8%
12.09
8.27
12.00
7.93
-
-
5.05
12.82
3.38
10.98
0.3
0.8
304.6
383
79.5%
11.88
7.35
11.82
7.95
11.82 10.75
5.05
20.50
3.28
19.60
0.5
2.5
494.7
616
80.3%
12.06
9.85
11.95
9.5
12.08 20.50
4.99
27.10
3.37
24.00
0.8
2.5
718.2
909
79.0%
12.00
13.2
12.00
15.25
12.00 35.00
4.98
27.00
3.40
23.70
0.8
2.5
998.5
1271
78.6%
+12V Ripple: 6.7 mV @ 500W

+5V Ripple: 3.4 mV @ 500W

+3.3V Ripple: 4.0 mV @ 500W
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


OTHER DATA SUMMARY: Enermax Galaxy EGA1000EWL-DXX02
DC Output (W)
40.8
53.6
91.5
154.6
196.9
304.6
494.7
718.2
998.5
Intake Temp (°C)
21
21
23
25
27
27
35
38
47
Exhaust Temp (°C)
27
27
30
33
36
39
47
55
71
Temp Rise (°C)
6
6
6
8
9
12
12
17
24
Fan Voltage (V)
4.9
4.9
4.9
5.1
5.9
7.0
11.9
11.9
11.9
SPL ([email protected])
29
29
29
30
35
36
50
50
50
Power Factor
.93
0.95
0.96
0.96
0.96
0.96
1.0
1.0
1.0

* AC Power with No Load, PSU power On: measurement blocked


* AC power on Standby: 13.7W
NOTE: The ambient room temperature during
testing can vary a few degrees from review to review. This can have an impact on the fan speed (noise) vs. power output curve. Please take this
into account when comparing PSU test data.

ANALYSIS

1. EFFICIENCY

The efficiency was a bit of a letdown. It seems the marketing department might have been overzealous with their "80-85% efficiency
from 20% to 100% load
" claim. On our test bed the PSU barely peaked 80%. Higher than normal measurement error might have sprung from some tinkering we
had to do in order to produce the 1kW power load needed. However, those changes don't apply until 500W and higher tests loads (where the 12V3 line was engaged), and the numbers below that are still
unimpressive. Even if your system is hardcore gaming, at typical idle to low loads (less than ~200W), it will likely be running at a not too thrilling 65-78% efficiency. Since heat
was up fairly dramatically in the higher power ranges, temperature probably
took its toll on the PSU efficiency.

2. VOLTAGE REGULATION

The voltage regulation was excellent. No matter what the load combination, values stayed pretty much where they were supposed to.
Perhaps this was a benefit dual 12V transformers. Voltages varied only 3% from target, and only
on the 3.3V rail. Other rails barely breached 1% at their worst.

3. RIPPLE

The AC ripple was vanishingly low! It's about on par with the random electrical noise you find in most cities. We can only imagine what kind of hardware was
necessary to make this happen, or maybe they had some spiffy new trick up their
sleeves. Either way the numbers (+12V 6.4mV @ 500W???) reflected a well built
power supply you could trust to supply darn well anything.

4. POWER FACTOR was excellent throughout the tests. At very low load, it varied a tiny bit,
but once we started demanding a little more from the PSU it hit the ideal 1.0
and stayed there.

5. LOW LOAD / CROSSLOAD PERFORMANCE

Our usual low / no load testing could not be done. That little Power Guard guy does its job quite well. We were
prevented from testing at very low power or using no load starting
conditions. Later on, we were held back from overdriving the system, too. Best
of all, when we were in proper operating range Power Guard left us well enough
alone. Included was that handy-dandy light and beep setup to explain the source
of an error. A clear table in the manual explained the meaning of each color
and light combination. The Power Guard shows us how it's done.

Neither could the crossload test be performed. Our usual procedure is to obtain ~75% load, almost entirely on the 12V lines, with only one amp each on the +5V and +3.3V lines. With a 1000W PSU, this is a pretty extreme load, some 750W in total. The Power Guard simply refused to let the PSU be turned on with this load, even if we built up to it by adding loading incrementally while the unit was running; it would shut down when the +5V and +3.3V lines got too low or when the 12V load got too high. If such conditions are not safe for the PSU, then the Power Guard's protective action is a good thing. Besides, it's hard to imagine how any system would demand over 740W on the 12V lines while pulling under 10W on the +5V and +3.3V lines.

One remote downside of the Power Guard: It is possible that in some unusual imbalanced loads, the Power Guard's protective action could cause a problem. In the context of the kind of system the Galaxy is desgined to be used, it's an unlikely scenario.

6. LOW AC VOLTAGE PERFORMANCE

Low VAC Test: Enermax Galaxy at 720W output
VAC
AC Current
AC Power
Efficiency
120V
7.62A
912W
79.0%
110V
8.41A
921W
78.1%
100V
9.34A
932W
77.2%
90V
10.5A
942W
76.4%

The Galaxy was unfazed by low AC voltage inputs at ~75% of rated power. Ripple stayed well within
limits and voltages stayed stable at all times. As expected, the efficiency dropped a bit as the input voltage was lowered.

7. TEMPERATURE & COOLING

This PSU was very well cooled at the lower levels. The fan controller (as you'll read in the next section) made sure of that. As we got close to maximum power, things got really hot. 55°C at 718W is not bad at all, judging by previous test results. But at full load, we hit 71°C and it would have risen higher had we run the test longer. The high rise in temperature had to do with the sheer amount of heat represented by nearly 1300W. That's the amount of power drawn by the PSU into the test box. Even at close to 80% efficiency, there was still over 270W of heat to remove from within the PSU — not to mention the role of the PSU fans in pulling the rest of the heat (1000W) out of the test box.

We also mentioned that there's a possible the mismatch in airflow between the two fans: The 80mm can only pull 44-46 CFM while the bigger one does more than double that. In any two fan push-pull setup such as this, the combined airflow through the two fans cannot be higher than the slower of the fans. As a result, the slot vents on the output cable side could act as a pressure valve for the higher airflow/pressure of the larger fan. This could mean some of the PSU heat was just being recycled back into the test box.

With the quiet ~45 CFM 120mm fan used to cool the text box, there was simply too much heat in the test box for the fans to cope. If you have a system that can really pull this kind of power, we'd suggest the equivalent of at least a hundred CFM airflow exhaust for the case.

8. FAN, FAN CONTROLLER and NOISE

Okay, here's the make or break when it comes to our reviews. PSUs can be
a lot of things and still pass with us, but this is where we get tough.

The Galaxy simply wasn't aimed at the quiet market. We mentioned
earlier that the unit's efficiency may peak around 500W. At the same time, fan voltage (along with speed and noise) also
hit its max. The Enermax Galaxy started at a relatively high 29 [email protected]
The noise quality was a mix of buzz, hum, rattling and resonance. It would be perhaps borderline acceptable, but it's basically an unpleasant sound. The noise level climbed steadily and linearly with load and temperature, which can only mean one thing: The priority here was to keep the PSU cool enough at all times. The noise reached an alarming 50 [email protected] at 500W load.

Contributors to the noise:

  • buzzy, rattling ball bearings
  • resonant clear plastic of the fan blades
  • linear temperature / voltage fan speed controller instead of stepped
  • turbulence caused by the dual fan
    setup

Suffice it to say that the acoustic performance is not charming. You can hear it for yourself in our recordings on the next page.

MP3 SOUND RECORDINGS

Each of these recording have 10 seconds of silence to let you hear the ambient
sound of the room, followed by 10 seconds of the product's noise.

  • Enermax Galaxy at less than 100W load, 29 dBA: One
    meter
    , One
    foot (30cm)
    There's no point listening to recordings at the higher levels. They just confirm that it's much too noisy.

Sound Recordings of PSU Comparatives — they are not exactly comparatives; we've never tested such a high power PSU before.

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

The Enermax Galaxy has excellent features and near-flawless electrical performance. The Power Guard worked well, with a tidy fault detection and explanation system, and it should be a strong benefit as long as it isn't overprotective in real systems. Voltage regulation was executed
with finesse, and ripple was superb. These are all good things. If the dual 12V transformers are part and parcel of this package, well, that's good and fine, too.

We've considered how the Enermax Galaxy might fit with the end user. If you
were thinking about buying this power supply you are undoubtedly using
it for gaming. (The Enermax folks talk about how it's also great for a server and so on, but no one buys a >$300 retail PSU for a server.) You'd need to believe that your system is the biggest, baddest gaming rig ever — or want everyone else to think so; otherwise, why would you consider such power and price tags? Perhaps you're one of the handful of gamers fantasizing about a 4-CPU / 4-GPU rig in the future and want to make sure you have enough power for that.

That being the case, a nice set of headphones with the volume
cranked up should cover the noise. Such an approach, however, is not in the SPCR spirit.

As regular readers know, low noise and high efficiency have long been our cornerstones for rating PSUs. The Galaxy doesn't cut it here. Efficiency only barely reached 80% on our test rig, and it suffered
badly at loads under ~100W; efficiency is the one aspect of electrical performance that's less than tops. The unit was a source of terrible noise, hitting maximum around where
it achieves best efficiency. It started a bit too noisy and got worse as soon as power output reached just a hundred watts. By 150W, it was 35 [email protected], which is already well beyond unacceptable; we consider [email protected] to be the upper limit for "quiet". In contrast, all of the comparative PSUs above (audio recordings of which are above) stay at just 25 [email protected] or less up to 200~300W output. Also, the noise character of these other PSUs is far smoother and more benign.

We should also address the price. The Galaxy comes with a healthy
supply of extras from the plethora of wires to a third transformer. These things
have to add up; how else to explain the >$300 market price? There
is only one thing to say: Whatever is driving up the price unnecessarily, keep it. Potential buyers will probably be happier with a leaner package and a lower price. Maybe some of the add-ons can be options.

Enermax has a strong, well earned reputation in the PSU field and
we look forward to trying many more of their units. Next time, let's hope we
get one more geared to the silent market.

Much thanks to Maxpoint USA for the Galaxy sample.

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