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Antec SU380 power supply (in NSK2400 case)

April 18, 2006 by Devon Cooke

Product
SU380 ATX12V power supply

supplied in Antec NSK2400 Media PC Case
Manufacturer
MSRP
N/A; US$99 for case & PSU

This power supply comes installed in the Antec NSK2400 media desktop case. The spec sheet for the NSK2400 calls the power supply a "New Solution Power ATX 12V
for AMD & Intel systems
". At the time of writing, this PSU can only be found in the NSK2400, and Antec appears to have no plans to make it available
as a separately packaged retail product.

So why not review the SU380 PSU along with the NSK2400 case and treat them together as one unit?

Because....

  • The NSK2400 case is quite unusual and required much examination, which means the review was already really long. Adding the PSU details would have made it way too long.
  • SPCR readers are among the most experimental PC assemblers. They will want to know about the performance of the case separate from the bundled PSU.
  • The NS2400 and SU380 may not always be bundled together.
  • The SU380 PSU turns out to be good enough to merit a stand-alone review.

This review assumes, naturally, that the SH380 PSU will be used in the NSK2400 case. It is also considerably shorter and condensed compared to our usual PSU reviews. You have to keep in mind that this PSU cannot be purchased on its own.


Link to Antec NSK2400 Review

The SU380 is a modern design, with full active power factor correction and auto-ranging AC input voltage.



PSU label: All the safety agency approvals and clearly marked output ratings.

Note minimum 12V power requirement.



SU380 comes installed in the NSK2400.

The PSU is cooled by an 80mm fan in a "straight-through" airflow configuration, much like Antec's NeoHE.
The intake vents are not particularly open, but there are enough of them that
the air should be drawn evenly across the whole inner panel.



Antec SU380 and Seasonic S12-330.

With the cover off, the SU380 bears a more-than-coincidental resemblance to
the Antec NeoHE and to the Seasonic S12 line of power supplies. With the exception with the design of
the heatsinks, the internal layout of the PCB appears to be identical to the
lower capacity Seasonic S12 models. A visual comparison below to the earlier Seasonic Super Silencer, which we recommended highly, leaves no doubt; here, the resemblance is unmistakable.



Antec SU380 and Seasonic Super Silencer 460.

The cable lengths should be plentiful no matter how complex the wiring gets.
The main ATX and Aux cables are both 25" long, which is longer than most
retail power supplies. All of the other cables have plenty of slack for where
they need to go. If anything, they are a touch on the long side, but fortunately
there's plenty of room to store slack in the space underneath the optical drive
bay.



Very long cables.

PSU TEST RESULTS

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.3
. The testing system is a close simulation of a moderate airflow
mid-tower PC optimized for low noise.

Ambient conditions during testing were 22°C and 20 dBA, 120V/60Hz.

OUTPUT & EFFICIENCY: Antec SU380











DC Output Voltage (V) + Current (A)

Total DC Output

AC Input

Calculated Efficiency
+12V1
+12V2
+5V
+3.3V
-12V
+5VSB
12.08
1.00
12.06
1.72
5.14
1.04
3.28
0.00
0.1
0.2
40.4
58
69.8%
12.08
2.00
12.07
1.72
5.13
2.10
3.28
1.92
0.1
0.3
64.7
85
76.6%
12.08
1.99
12.05
3.29
5.12
3.11
3.28
1.91
0.2
0.5
90.7
115
79.2%
12.05
4.02
12.00
4.96
5.12
4.10
3.28
3.88
0.3
0.8
149.3
183
81.6%
12.04
6.98
12.00
4.96
5.11
6.02
3.28
4.75
0.4
1.1
200.2
238
84.1%
12.02
6.98
11.95
8.05
5.11
7.01
3.28
6.54
0.5
1.3
249.9
301
83.0%
12.00
8.23
11.91
9.53
5.11
7.84
3.28
9.81
0.6
1.6
299.7
369
81.2%
11.98
11.17
11.88
11.14
5.08
11.6
3.29
10.62
0.8
2.0
379.6
482
78.8%
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: Antec SU380
DC Output (W)
40.4
64.7
90.7
149.3
200.2
249.9
299.7
379.6
Intake Temp (°C)
25
26
28
32
35
39
41
44
Exhaust Temp (°C)
27
29
31
36
38
41
42
47
Temp Rise (°C)
2
3
3
4
3
2
1
3
Fan Voltage (V)*
4.4
4.4
4.4
4.8
7.0
8.8
10.2
11.0
SPL ([email protected])
24
24
24
25
32
38
40
42
Power Factor
0.99
0.99
0.99
1.00
0.99
0.99
0.99
1.00
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.



*Note that our test rig is a much more thermally strenuous environment
than the NSK2400, so the fan voltage would not rise as fast under actual
use.

ANALYSIS

1. VOLTAGE REGULATION was excellent. Both the +12V and +3.3V rails
were within ±1% of their nominal values throughout the test. The +3.3V
line did not vary at all until the very last test point, when it rose
by 0.01 volt. Those who like to tweak their RAM settings should be very happy
with this. The +5V rail was also very well regulated, although it was consistently
high throughout the test. Most importantly, though, it stayed
high through the test. The total range of variance was 0.06 volts — just
a tiny bit more than a 1% variance.

2. EFFICIENCY was also excellent, although it needed a fairly high load before it really shone. Efficiency was well above
80% between 150~300W output. The 84% peak is exceptional
for a power supply just bundled with a case. The SU380 actually reached
a higher peak efficiency than the Seasonic S12-430, despite the fact that
the S12 on its own costs nearly as much as the NSK2400 and the SU380 together.

3. MINIMUM LOAD was actually much lower than indicated on the PSU label. The PSU powered up on our test bench with no load whatsoever. This bodes well for the lower powered rigs that are typical of media PCs. (Keep in mind, however, that shutdown problems in real systems are sometimes caused when the motherboard shuts the PSU down, not just the PSU on its own.)

4. POWER FACTOR - The power factor stayed above 0.99 throughout the
testing. Our Extech power meter even reported it as being at the ideal value
of 1.00 at a couple of points. Presumably, it never actually
reached this value (a practical impossibility), but it's safe to say that
the difference was beyond than the precision of our measurement tools.

5. TEMPERATURE & COOLING - Thermally, the SU380 has nothing to worry about. The largest temperature rise
between the intake and the exhaust was a measly 4°C, reached just before
the fan began to speed up. If anything, the SU380 is overcooled — Antec
could probably have gone with a quieter medium or low speed fan without worrying
about the internal temperature.

6. FAN, FAN CONTROLLER and NOISE - In fact, that is exactly what Antec should have done, since the minimum noise
level was disappointingly high. For those less obsessive about noise, it would
still be considered quiet, but given the large number of power supplies with
lower base levels it's a shame that a quieter or at least slower speed fan wasn't used. The choice of
fan is the one part of the SU380 that isn't top-notch. Obsessive silencers
will no doubt find it a perfect candidate for a fan swap.

Even at its lowest level, the fan had a distinctly tonal characteristic that
made it more difficult to ignore than the broadband whoosh of
airflow. The noise had the beginnings of a whine, though it was low enough in
pitch that it came off as more of a growl. The whine quickly became apparent
(and noisy) once the fan began to increase in speed.

Fortunately, the fan is very unlikely ever to increase in speed, thanks to
the separate thermal zone for the PSU in the NSK2400 case. With the fresh air intake ducts located just a couple inches away from the intake vent of the PSU itself, the intake air temperature would be the same as the external room temperature. In the test setup, the room temperature was 22°C. Given that the internal temperature of the test rig had to reach 32°C and 150W output load before the fan started to ramp up, in practical use, this means the PSU fan will probably rarely, if ever, ramp up in speed. In the NSK2400, the SU380 can be treated as a power supply that runs
at a constant 24 [email protected], no matter what the load (unless the room temperature exceeds 30°C — too hot to be lounging around near the computer, in our view). With a fan swap, this noise
floor could be reduced without endangering the power supply because of the fresh air intake setup of the NSK2400.

MP3 Sound Recordings of Antec SU380

Antec
SU380 @ <90W (24 [email protected])


Antec
SU380 @ 150W (25 [email protected])

There was no need for recordings at higher power
levels; it's unlikely that the PSU will ever get that loud
in the NSK2400.
Sound Recordings of Comparative PSUs



HOW TO LISTEN & COMPARE

These recordings were made with a high
resolution studio quality digital recording system. The microphone was 3" from
the edge of the fan frame at a 45° angle, facing the intake side of the fan to
avoid direct wind noise. The ambient noise during all recordings was 18 dBA or
lower.

To set the volume to a realistic level (similar to the original), try playing the Nexus 92 fan reference recording and setting the volume so that it is barely audible. Then don't reset the volume and play the other sound files. Of course, tone controls or other effects should all be turned off or set to neutral. For full details on how to calibrate your sound system to get the most
valid listening comparison, please see the yellow text box entitled Listen to
the Fans
on page four of the article
SPCR's Test / Sound Lab: A Short Tour.

CONCLUSION

The SU380 is excellent in every respect
except noise, and even that is not a big deal thanks to the fresh air
intake setup of the case it is supplied in. Considering the unit comes in the NSK2400 case which has a MRSP of just $99, it's extremely good value
for money.

Link to Antec NSK2400 Review

Other SPCR Articles of Related Interest

Antec NeoHE430 power supply

Seasonic Super Silencer 400 power supply

* * *

Antec NSK2400 discussion thread in the SPCR forum.

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