With the SS-1050W XP3 Seasonic has a high end power supply in its portfolio which offers 1050 Watt output power. When looking for an 80Plus certificate one can find a platinum sticker on this PSU. Furthremore Seasonic is one of the very few power supply manufacturers, that actually own fabs. Therefore they don't need to rely on OEM channels. We're already really curious to see what this 210 Euro power supply is capable of.
On the following pages we will
have a close look at the Seasonic Platinum Series 1050W XP3 power supply and
show you what it can do.
Delivery and Specifications
|1 x ATX 20+4 pin
|2 x EPS/ATX 12V 8 & 4+4 pin
|8 x PCI-E 6+2 pin
|1 x 2 SATA
||53, 68 cm
|4 x 3 SATA
||53, 68, 83 cm
|1 x 2 Molex
||35, 50 cm
|2 x 3 Molex +
1 x 2 Floppy
||55, 70, 85 cm
delivery of the SS-1050W XP3 is adequate. Since PSUs with this kind of output power
are often used for PCs with five or more graphics cards, it would have been nice
if Seasonic added another pair of PCI-E 6+2 Pin cables, which can be connected
to the EPS/ATX 12V 8Pin connector.
With this power supply
Seasonic is offering a single rail design regarding 12V. In total you get 87A,
which can be turned into heat by the graphics cards for instance.
Specifications (according to Seasonic)
|+ 3.3 V
||1'050 Watt (Total)
|+ 5.0 V
|+ 12 V
|- 12 V
|+ 5 Vsb
SS-1050XP3 has been 80Plus Platinum certified. This means, that the efficiency of
this PSU should be above 90% at 20% load, above 92% at 50% load and above 89% at
At this point the feature list:
- 80Plus Platinum
- OVP, UVP, OCP, SCP, OPP, OTP
- Dimensions (W x H x D): 150 mm x 86 mm x 190 mm
- 140 millimeter fan
- Passive while below 35% load
- Warranty: 7 Years
- Price: ~250 CHF / ~210 Euro
A Look Inside
The first hint for a high Quality PSU can be seen when taking a first look at it.
There is a nice design and high quality case.
Seasonic decided to go for a Sanyo Denki San Ace Fan, which is a very high end
fan and unfortunately it can't be found too often in todays power supplies.
Right at the Input there is an extensive filtering stage, which has been place
on a separate PCB.
At the PCB the transient filtering stage continues with one X cap, four Y caps, a CM and
DM choke as well as a MOV (Metal-Oxid-Varistor).
Additionally there is a NTC thermistor for inrush curent limitation. A mechanical
relais shorts the NTC Thermistor for normal operation.
The transient filtering stage is well done. We have not seen many PSUs with such
an extensive input filtering stage.
In the case of the PFC Booster Seasonic makes use of a Schottky diode and the
APFC itself is being controlled through a chip from On Semiconductor. Apart from
that this power supply features three APFC capacitors, which all come from
Nippon Chemi-Con (KMR Series; 330uF, 420V, 105°C) and are therefore of very high
quality. Four Infineon 5R250P mosfets (550V, 0.25Ohm, 27 A) are used on the primary side of
the LLC resonance concerter and it is being controlled via a CM6901.
The primary side of this PSU is rock solid. Especially the costly transient
filtering stage and the high end japanese Nippon Chemi-Con Capacitors are
A quick look a the secondary side show a rather big cooler, which appears to be
not connected to any chips or mosfets. As soon as we turn the powersupply around
we find four FMCS015N90B mosfets, that are connected to this heatsink. Also on
the secondary side Seasonic is only using Nippon Chemi-Con capacitors in order
to keep quality on a very high level. Checking for voltage regulation modules,
we find those on a daughter PCB and in fact there are Infineon BSC0906NS mosfets
in place, which are being controlled by an APW7159 PWM controller.
Result Analysis and Discussion
The 80Plus Platinum certification
requirements (87% - 90% - 87%) are surpassed especially at 20% Load. The full Load
efficiency is a bit higher at 230V AC. This is the case with most of todays PSU's an it mainly
originates from the reason of lower losses in the AC filtering stage and the PFC at
230V AC. The 230V AC 100% Load efficiency is 90.68%.
The Voltage Regulation of
this PSU is very good. It makes use of a DC-DC topology. This means, that the
SS-1050XP3 is mainly a 12V PSU and then generates its 5 and 3.3V from 12V.
This is a modern approach, and since the Load is mainly on 12V it makes a lot of
sense. For almost any PSU which makes use of this topology crossload tests do
not present a problem.
If we listen closer with the power supply, we don't here anything
at 20 percent load. The SS-1050XP3 is a semi passive power supply and the fan
kicks in, when 35 percent load is reached. It keeps spinning until the load goes
below 25 percent. This ensures adequate internal temperatures under all
circumstances. When demanding 50 percent load from this unit, the noise level
can be described as silent and when there is 100 percent load, the unit is well
The noise values are good. Only the 28mV
at 12V are a bit high, but since the 12V ripple performance drastically improves
with just little less 12V load, we don't judge this as a negative point.
With the SS-1050XP3 Seasonic
released an absolute high-end power supply. There is a costly AC filtering stage, an extremely high end fan, and
the massive use of Nippon Chemi-Con capacitors, which - amongst other parts -
add up to a great product. All the components mentioned comply with highest
standards and its hard to find other PC PSU's which are built according to similar
Furthermore this PSU is very reliable even if you plan with it for long term usage.
Compared to the predecessor Seasonic decided to add adequate cooling for the 12
volt mosfets on the back of the PCB, which means, that nothing will be
overheating even if you drive this unit above specifications. The manufacturer
is actually under specifying this unit, since it can cope with loads of 1200
Watt without breaking a sweat. Should you be building a high-end system, that is
to continually pull around 1000 Watts, this extra headroom is going to mean
piece of mind to you.
This high-end power supply is absolutely worthy of receiving five out of five