ocaholic - PSUs > Seasonic Platinum Series SS-1050W Snow Silent Review

[pagebreak]

Preview

Page 2 - Preview

[pagebreak]

Delivery and Specifications

Delivery
Cable	Length
1 x ATX 20+4 pin	60 cm
2 x EPS/ATX 12V 8 & 4+4 pin	65 cm
8 x PCI-E 6+2 pin	60 cm
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

The delivery of the SS-1050W Snow Silent XP3 is adequate. Since PSUs with this kind of output power are often used for PCs with four 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)
Voltage	Current	Power
+ 3.3 V	25 A	125 Watt	1'050 Watt (Total)
+ 5.0 V	25 A	125 Watt
+ 12 V	87 A	1'044 Watt
- 12 V	0.5 A	6 Watt
+ 5 Vsb	3.0 A	15 Watt

The SS-1050XP3 Snow White 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 100% load.

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: ~280 CHF / ~240 Euro

Page 3 - Delivery / Specs

[pagebreak]

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, a white exterior 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 a 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 excellent.

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.

Page 4 - A Look Inside

[pagebreak]

Result Analysis and Discussion

Efficiency
Load	Pin(W)	Pout(W)	Efficiency
20 %	191.13	173.96	91.02 %
50 %	472.77	435.46	92.11 %
100 %	968.92	870.93	89.89 %

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%.

Output Stability
Load	Rail	Loading(A)	Output(V)
20 %	5V	4.17	5.09
	3.3V	4.17	3.35
	12V	14.6	12.11

50 %	5V	10.47	5.11
	3.3V	10.47	3.38
	12V	36.5	12.12

100 %	5V	20.95	5.08
	3.3V	20.95	3.39
	12V	72.98	11.98

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.

Noise
Load
20 %	Noiseless
50 %	well audible

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 audible.

Noise/Ripple
Voltage	Noise/Ripple Vpp
3.3V	0.020
5V	0.013
12V	0.028

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.

Page 5 - Result Analysis and Discussion

[pagebreak]

Conclusion

With the SS-1050 XP3 Snow Silent 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 guidelines. 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. Thanks to the white exterior this power supply is perfectly suitable for modding projects.

This high-end power supply is absolutely worthy of receiving five out of five stars.