Power supplies which employ Power
Factor Correction (PFC, or A-PFC) help ensure efficient conversion of AC to DC
voltage, and reduce the amount of energy wasted as heat. That means a quieter
120mm fan can be used, and less noise for your ears.
PCSTATS
tests power efficiency with the aid of an Extech Model 380803 Power Analyzer.
The meter is located between the mains 120AC supply and the power supply, and a
120W dummy load is connected to the power supply being tested. Power jitter is
measured with a Mastech MS8230B Multimeter at the device power connectors. The
test apparatus and power meters are shown below.
The power supply looking device is
actually the 120W dummy load. To the right is a standard Voltmeter, and in the
background the Extech Model 380803 Power Analyzer (with readings for Watts,
PFC/KHz, source voltage (AC) and Amperage).
Power Jitter Observations -
Motherboard |
|
Voltage jitter is
read by accessing the power options displayed in the motherboard BIOS, with the
system obviously in an unloaded state. Voltages were read from the BIOS of a
motherboard.
Power Jitter Observations
- Motherboard |
Listed Voltages |
Lower Voltage |
Upper Voltage |
Jitter |
+3.3V |
3.30V |
3.31V |
0.1V |
+5.0V |
4.91V |
4.91V |
0V |
+12V |
12.06V |
12.07V |
0.1V |
There's really not much to say here, the X-750 was
rock solid in this test.
When looking at the Seasonic Power Supply test results we see two values, wattage
and volt-amps. Since it might not be clear what they measure, here's a brief
overview.
The
volt-amp (VA) value is how much real power is being consumed by the power supply
being tested to provide the wattage (W) value. The higher the VA value is, the
more electricity is being used by the power supply. Because no electrical device
is 100% efficient, there will always be some loss when converting AC to DC. The
closer the volt-amps and wattage figures are to each other, the more efficient a
power supply is. This is called the Power Factor: wattage / volt-amps =
PF.
Since we're testing with a 120W dummy load, the
load on the power supply (wattage) should be as close to this figure as
possible. Anything above this load in apparent power describes the overhead and
wasted energy (given off as heat) for the particular power supply being tested.
For the unloaded tests, the wattage and volt-amp figures should be as close as
possible to one another. The lower the figures are, the less power is being
wasted.
Measurements were taken with an Extech 380803 Power
Analyzer.
Seasonic Power Load Tests |
Power Supply
Model |
Wattage |
Test
Type |
Loaded |
Unloaded |
Seasonic SuperTornado |
400 W (A-PFC) |
Active Power |
177 W |
6 W |
Apparent Power |
182 VA |
7 VA |
Vantec iON2 |
350 W |
Active Power |
192 W |
10 W |
Apparent Power |
277 VA |
21 VA |
Antec TruePower 330 |
330 W |
Active Power |
195 W |
22 W |
Apparent Power |
289 VA |
38 VA |
Ultra X-Connect Green UV 500W |
500 W |
Active Power |
193W |
22 W |
Apparent Power |
307 VA |
40 VA |
AOpen Silent Power AO400-12AHN |
400 W |
Active Power |
179W |
9 W |
Apparent Power |
275 VA |
18 VA |
Seasonic S12-430 |
430 W (A-PFC) |
Active Power |
179W |
6W |
Apparent Power |
180VA |
9VA |
PC Power and Cooling Turbo-Cool 510 Express/SLI |
510 W (A-PFC) |
Active Power |
200 W |
29 W |
Apparent Power |
202 VA |
32 VA |
HEC Ace Power 580UB |
580 W |
Active Power |
183 W |
12 W |
Apparent Power |
272 VA |
26 VA |
HEC Win 550UB |
550 W |
Active Power |
184W |
10W |
Apparent Power |
263VA |
22VA |
Akasa PowerPlus AK-P550FF |
550 W (A-PFC) |
Active Power |
194W |
38W |
Apparent Power |
197VA |
40VA |
AOpen Prima Power AO700-12ALN |
700 W (A-PFC) |
Active Power |
172W |
3W |
Apparent Power |
181VA |
9VA |
PC Power & Cooling Turbo-Cool 1KW |
1000 W (A-PFC) |
Active Power |
205W |
25W |
Apparent Power |
207VA |
32VA |
Seasonic S12 600 |
600 W (A-PFC) |
Active Power |
164W |
7W |
Apparent Power |
173VA |
9VA |
Mushkin Enhanced XP-650 |
650 W |
Active Power |
192W |
22W |
Apparent Power |
279VA |
43VA |
Seasonic S12 Energy Plus SS-650HT |
650 W (A-PFC) |
Active Power |
150W |
7W |
Apparent Power |
150VA |
10VA |
Seasonic M12 700W |
700 W (A-PFC) |
Active Power |
161W |
8W |
Apparent Power |
165VA |
11VA |
Corsair HX620W |
620 W (A-PFC) |
Active Power |
171W |
8W |
Apparent Power |
173VA |
12VA |
Zalman
ZM600-HP |
600 W (A-PFC) |
Active Power |
173W |
5W |
Apparent Power |
175VA |
9VA |
HEC Zephyr 650 |
650 W (A-PFC) |
Active Power |
185W |
12W |
Apparent Power |
190VA |
17VA |
GlacialPower GP-PS550BP |
550 W |
Active Power |
178W |
6W |
Apparent Power |
269VA |
17VA |
Cooler Master Real Power Pro 750W |
750 W (A-PFC) |
Active Power |
158W |
6W |
Apparent Power |
163VA |
9VA |
Cooler Master Real Power Pro 750W |
750 W (A-PFC) |
Active Power |
158W |
6W |
Apparent Power |
163VA |
9VA |
Seasonic S12 II
500W |
500W (A-PFC) |
Active Power |
145W |
7W |
Apparent Power |
148VA |
10VA |
Enermax Infiniti
720W |
720W (A-PFC) |
Active Power |
179 W |
12 W |
Apparent Power |
181 VA |
18 VA |
COOLMAX GREEN
POWER CUQ-1200B |
1200W (A-PFC) |
Active Power |
172 W |
9 W |
Apparent Power |
193 VA |
12 VA |
PC Power & Cooling Silencer
750 Quad |
750 (A-PFC) |
Active Power |
168 W |
12 W |
Apparent Power |
175 VA |
15 VA |
Enermax Galaxy
EGX850EWL |
850 W (A-PFC) |
Active Power |
184 W |
11 W |
Apparent Power |
193 VA |
16 VA |
Seasonic M12D 750 |
750W (A-PFC) |
Active Power |
169W |
7W |
Apparent Power |
173VA |
9VA |
Seasonic S12D 850 |
850W (A-PFC) |
Active Power |
148W |
7W |
Apparent Power |
149VA |
10VA |
Seasonic X-750 |
750W (A-PFC) |
Active Power |
139W |
6W |
Apparent Power |
141VA |
8VA | |
The Seasonic X-750 power supply uses 139W of power when
a 120W load is hooked up, which is 86% efficiency, right in line with its 80+
Gold rating! I honestly did not think that Seasonic would be able to top the excellent
M12D-750 modular unit that PCSTATS reviewed earlier this year, but with X-750
Seasonic has one-upped themselves again. It's no
surprise that the X-750 is currently the most efficient power supply that PCSTATS has tested!
Conclusions: Seasonic Proves its
Mettle
The Seasonic X-750 is a rock-solid power supply that would
be a worthy foundation to any enthusiast or gamer PC. The term
"rock-solid" applies to the build quality of this power supply, the design
approach by Seasonic and the 80Plug Gold power efficiency rating. No matter how
you cut it,
Seasonic have manufactured a very satisfying PSU - that's evident the moment you
lift it out of the box.
The modular
cables that come with the Seasonic X-750 are sufficient to meet pretty much all
PC configurations you can think of. With respect to videocards, this 750W PSU can comfortably
support two dual-power high-end PCI Express videocards or four single-power mainstream PCI Express
videocards. That's a lot of graphics card might.
On
the peripheral side we find the X-750 offers up eight SATA/molex power connectors each, over six
bundles. There are however only five ports on the back of the power supply,
so not every cable bundle can be used.
Noise levels on the X-750 were low enough as
to be inaudible. The 120mm Sanyo Denki fan is designed for silence, and because
of the low heat levels produced by the X-750 it doesn't have to spin
all that quickly either.
Best of all, the Seasonic X-750 power supply actually lived up to its 80 PLUS
Gold certification. Even at lower loads PCSTATS is forced to test with (120W),
the X-750 was able to maintain an 86% efficiency rating. Retailing for in
the region of $210 CDN ($200 USD, £110 GBP),
the X-750 isn't cheap, but cheap is the last thing
you want from a power supply. The Seasonic X-750 is well-built, stable and
highly efficiency, and that's worth every penny if you're a PC enthusiast.
Recommended.
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