Seasonic S12 430-Watt Power Supply Review

Sea Sonic is a rising competitor in the consumer power supply market, dedicated to developing and manufacturing green and silent power supplies. To keep with their promise, the Sea Sonic S12-430W, contains numerous features to keep no only their power supply, but your computer running silent.

The packaging done by Sea Sonic is impressive with its nice colors and clear graphics as well as the cute handle on the top (purpose of handle is unknown, but I like it). The box also lists a ton of the unit’s special features on the back.

The following is a list of some of the general features included with the S12:

Seasonic S12 Power Supply Features
  • Complies with the latest Intel ATX 12V v2.0 spec.
  • Supports latest Pentium 4’s and AMD Athlon 64/64FX
  • Extremely High MTBF (>100,000 hours)
  • Supports PCI Express and Serial ATA
  • Double-ball bearing Fan
  • Dual +12V Rails
  • External Fan Control Output
  • Super High Efficiency (up to 80%)
  • Active Power Factor Connection
  • Smart & Silent Fan Control
  • 120mm Cyclone Fan
  • Twisted & Tidy Wires
  • Easy Swap Connectors
  • Dual VGA Power Connectors
  • Cable Management Kit (Dr. Cable)
  • All-in-1 Connector Design
  • 3 Year Warranty

Sea Sonic ships everything you would need for an easy installation of their power supply. Included in the box is the user manual, mounting screws, case badge, power cord, Dr. Cable cable management kit, external fan control output cable, and of course the power supply with pre twisted wires, patented easy swap connectors, and a 120mm cyclone cooling fan. The power supply is a nice flat black color which I really like.

The back of the power supply is a nice honey comb design to allow for maximum ventilation and to keep with Sea Sonics’ idea of having a silent product. Unlike most power supplies, these units do not have a switch to go from 115v to 220v; they have Universal Free AC input, which allows the unit to select the voltage on its own. This is a very handy feature to prevent any problems that may be caused by having the switch set wrong.

The S12 comes with pre-twisted wires on all the cables, which allows for better cable control and cooling in the computer. Also, the ATX motherboard connector can be switch from 20-pin to 24-pin depending on the application. Also shown is a serial ATA connector, the dual CPU power connector, and the connector to monitor the units fans through the motherboard.

Installation of the power supply was fairly straight forward and simple. The pre-twisted wires made routing the cables extremely easy. All the cables were plenty long enough even for this full tower case. The easy swap connectors are very helpful, especially when switching drives. They work by squeezing the tabs on both sides of the connector, and then it just pops out of the drive or other object that it is plugged into.

Sea Sonic included Dr. Cable with their power supply, which is a cable management system for their power supply; it includes 2 sizes of split tubing (or cable wrap), 1 cable mount, and a bundle of cable ties (or zip ties). The directions to install Dr. Cable are straight forward, which are included in detail in the user manual for the power supply. It did help out with the wires in the case, even with the long cables and the number wires already in the case. When the split tube was put onto the ATX motherboard connector, it did make the wire a lot stiffer and harder to move.

Now let’s test this thing and see what it can really do.

System specs
  • MSI PM8M-V
  • P4 2.25 GHz Northwood w/ 92mm Cooling fan
  • 1GB PC2700 DDR
  • Abit Ti-4200 128MB 8x AGP OTES
  • Lite-On DVD and CD-RW Drives
  • 2x120mm Fans
  • 2xUV Cathode

When the computer was first booted with the S12-430 installed, there was a noticeable difference in the loudness of the computer. With the two 120mm fans connected to the external fan control function on the low setting, the system was much quieter.

Motherboard Monitor v. 5.3.7 was used to gather all voltage data. At default CPU speed, all the voltages were in their normal range and not fluctuating.

Prime95 was then used to test the CPU at full load. The 5v went up very slightly while the 12v dropped slightly, even though they changed it wasn’t significant enough to be concerned about.

The computer was then overclocked from 2.25 GHz to 2.41GHz. When the system was rebooted there was no changed in the readings from the stock idle voltages to the overclocked idle voltages.

Prime95 was run once again to test the overclocked CPU at full load. Again, the values of the PSU did not change from the stock full load voltages.


Sea Sonic has really proven that they make a quality power supply. It doesn’t matter if you need it in a normal consumer PC or a high end server; it has proven to be solid and stable. They have proven their dedication to producing green and silent products with the low noise and power consumption.

Sea Sonic is also appealing to the users that want good efficient airflow by packaging their Dr. Cable cable management system with the unit. And for those that want a quieter PC, using a quiet fan with a unique ventilation system on the power supply and letting the product control the case fans, Sea Sonic provides this option.

Overall this is an excellent power supply and a high quality computer component.

REPORT CARD : Seasonic S12 430 Watt Power Supply
category rating comments
Quality 5 Solid design with many features to appeal to all users.
Performance 5 Rock solid on both stock and overcloced processors.
Installation 4 Cables are a little long, even for full tower cases. Dr. Cable made ATX motherboard connector stiff and hard to move. Easy-swap connectors allowing for easy switch of peripherals.
Aethetics 5 Flat black finish looks great and quieter than most power supplies, and can quiet a system down.
Value 4 A little high for a 430 wayy PS, but worth it with all the features.
FINAL VERDICT: 5 out of 5 stars

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