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
1x2 + 3x3 SATA	55, 90 cm
1x2 + 2x3 Molex + 1 x 2 Floppy	55, 90 cm

The delivery of the SS-1250XM 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.




The design is based on one single 12V rail with a whopping 104A. However this 12V Rail is then splitted into four Rails for the distribution. The 4 Rails are then OCP protected induvidually. In our opinion it is good that Seasonic splitted the rail (also because of security reasons) but it would be even better if Seasonic mentions it somewhere in the descriptions.
Seasonic provides missleading information. Aditionally we think, that the four Rails are too heavily OCP protected. Even with normal usage it could be that this device goes into OCP status (for example: a 45A Rail providing four PCIe 8Pin - with two Radeon HD 6990 cards on them this rail would go OCP). It's very sad that Seasonic does not provide the correct information there.

Specifications (according to Seasonic)
Voltage	Current	Power
+ 3.3 V	25 A	150 Watt	1'250 Watt (Total)
+ 5.0 V	25 A
+ 12 V	104 A	1'248 Watt
- 12 V	0.5 A	6 Watt
+ 5 Vsb	3.0 A	15 Watt

This PSU is based on one 12V rail that offers 104A. However this rail is split internally into four separate rails.
How the power has been split on the different rails can be seen in the following table:

Specifications (reality)
Voltage	Current	Power
+ 3.3 V	25 A	150 Watt	1'250 Watt (Total)
+ 5.0 V	25 A
+ 12 V1	30 A	1'248 Watt
+ 12 V2	30 A
+ 12 V3	45 A
+ 12 V4	45 A
- 12 V	0.5 A	6 Watt
+ 5 Vsb	3.0 A	15 Watt

The Rails are connected to the connectors as follows:

• 12V1 - 30A
  - 24Pin ATX
  - 2x EPS/ATX 12V 8Pin
   
• 12V2 - 30A
  - 2x PCI-E 6+2 Pin
   
• 12V3 - 45A
  - 4x PCI-E 6+2 Pin
   
• 12V4 - 45A
  - Molex
  - SATA
  - 2x PCI-E 6+2 Pin

Seasonic has done this very badly. We understand that a single rail with 104A is potentiall dangerous. However we would like to see an optimized Rail distribution as well as a more useful OCP protection per rail. 4 x 55A or similar would make sense in our opinion..




The SS-1250XM has been 80Plus Gold certified. This means, that the efficiency of this PSU should be above 87% at 20% load, above 90% at 50% load and above 87% at 100% load.
Feature-list:

• 80Plus Gold
• OVP, UVP, OCP, SCP, OPP, OTP
• Dimensions (W x H x D): 150 mm x 86 mm x 190 mm
• 120 millimeter fan
• Semipassive fan (below 20% load)
• Warranty: 5 Years
• Price: 250 CHF

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Page 1 - Introduction

Page 2 - Preview

Page 3 - Delivery / Specs

Page 4 - A Look Inside

Page 5 - Input/Output Power and Efficiency

Page 6 - Result Analysis and Discussion

Page 7 - Conclusion

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