ocaholic - PSUs > Seasonic Platinum Series SS-660XP2 Review

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Photo Gallery

Page 2 - Photo Gallery

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Delivery and Specifications

The Seasonic SS-660XP2 Platinum Series power supply is a fully modular design PSU which means that all the cables, including both the 24-pin ATX and two 8-pin EPS ones are modular as well.

Cables
Cable	Length
1 x ATX 20+4 pin	65 cm
2 x EPS/ATX 12V (8 & 4+4) pin	69 cm
4 x PCI-E 6+2 pin	64 cm
1 x 3x Molex	42, 54, 68 cm
1 x 2x Molex	32, 46 cm
2 x 4x SATA	41, 53, 65, 78 cm
1 x 2x SATA	32, 44 cm

Connectivity is perfect for a power supply of this wattage, there is also a molex to floppy adapter.

Specifications
Voltage	Current	Power
+ 3.3 V	25 A	125 Watt	660 Watt (Total)
+ 5.0 V	25 A	125 Watt
+ 12 V	55 A	660 Watt
- 12 V	0.5 A	6 Watt
+ 5 Vsb	3.0 A	15 Watt

The Seasonic SS-660XP2 Platinum Series power supply uses a single +12V rail design and this 660W model can provide up to 55Amps on it.

The SS-1250XM is 80Plus platinum certified. This means, that the efficiency of this psu should be over 90% at 20% load, over 92% at 50% load and over 89% at 100% load.

The full specification list includes:

80Plus Platinum
OVP, UVP, OCP, SCP, OPP, OTP
Dimensions (W x H x D): 150 mm x 86 mm x 160 mm
120 millimeter fan
Semipassive fan (below 30% load)
Warranty: 7 Years
Price: 130 CHF

The first thing that you might notice on the list is the impressive 7 year warranty. While most PSUs are limited to 3-year one and some high-end ones come with 5-year warranty, Seasonic really surprised with 7-year warranty period, which only shows that this is a real high-end PSU in which Seasonic has full confidence. It uses pretty standard 160mm long case and also comes with a switch on the connector panel that takes it into hybrid (semi-passive) and normal (silent) operation modes.

Page 3 - Delivery / Specs

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A Look Inside

Right at the input there is the filter PCB. At the PCB is the transient filtering stage which continues with two X, four Y, a CM and DM chokes as well as 4 MOVs (Metal-Oxid-Varistor). Additionally there is an NTC Thermistor for in-rush current limitation. A mechanical relay shorts the NTC Thermistor for normal operation. The Transient filtering stage is pretty impressive and we have not seen that many PSUs with such good input filtering.

Two GBJ 1506 (15A) are used for rectifying. The PFC Booster consists out of two IPP50R250CP Mosfets (550V, 0.25Ohm, 13A) and a C3D06060 (600V, 6A, Qc 16nC) SiC Schottky Diode. The APFC is controled by a NCP1654 from ON Semiconductor. The NCP1654 has a Gate driver performance of 1.5A. This PSU has 2 APFC capacitors from Nippon Chemi-Con (KMR series; 220uF, 420V, 105C each). Four IPP50R399CP (560V, 0.4Ohm, 9 A) Mosfets are used on the primary side of the LLC resonance converter. The LLC resonance converter is controlled by 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 high end.

The primary side of this PSU is very similar to the one found with the Seasonic X-Series PSUs.

The secondary side however differs a lot. The 12V MOSFETs are no more placed on the bottom side of the main PCB, but on a daughter PCB with direct heatsink. Seasonic used of high end Japanese Nippon Chemi-Con capacitors on front side and pairing them up with cheaper Enesol solid caps on the secondary side points out that Seasonic had to save some money here and did not go for a full Nippon Chemi-Con design.

Page 4 - A Look Inside

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Input/Output Power and Efficiency

Page 5 - Input/Output Power and Efficiency

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Result Analysis and Discussion

Efficiency 115V
Load	Pin(W)	Pout(W)	Efficiency
20 %	146.82	132.87	90.50 %
50 %	360.36	331.54	92.00 %
100 %	743.62	661.83	89.00 %

The platinum Energy certification requirements (90%, 92%, 89%) are fulfilled at 50 and 100% load without any margin. The full load efficiency is a bit higher at 230V AC. This is the case with most PSUs on the market and comes as a results of lower losses in the AC filtering and in the PFC at 230V AC. The 230V AC 100% Load efficiency is 90.93%.

Output Stability
Load	Rail	Loading(A)	Output(V)
20 %	5V	2.46	5.056
	3.3V	2.47	3.328
	12V	9.00	12.14
	5VSB	0.49	5.056

50 %	5V	6.15	5.03
	3.3V	6.14	3.33
	12V	22.43	12.10
	5VSB	1.225	5.04

100 %	5V	12.27	5.043
	3.3V	12.26	3.307
	12V	44.97	12.06
	5VSB	2.64	4.965

The Voltage Regulation of this PSU is very good. It makes use of a DC-DC approach. That means, that this PSU is mainly a 12V PSU and then it generates both 5V and 3.3V from that same 12V.
This is a very modern approach, and since the load is mainly on the 12V rail, this approach makes a lot of sense. As most PSU which use this topology, the Voltage regulation and the Crossload test do not present a problem.

Noise
Load
20 %	Noiseless
50 %	Very silent
100 %	Silent

As we already noted earlier, Seasonic decided to use a Sanyo Denki San Ace 120mm fan for the SS-660XP2 Platinum Series power supply unit and it definitely does a great job as the PSU is completely noiseless at 20 percent load, very silent at 50% and even silent at 100% load.

Noise/Ripple
Voltage	Noise/Ripple Vpp
5V	0.0191
12V	0.0319
-12V	0.0163
3.3V	0.0186
+5VSB	0.0096

The voltage noise values are good.

Page 6 - Result Analysis and Discussion