Seasonic is a well-known manufacturer of power supply units, its S12 series having been an etalon of a silent PSU. Today I am going to tell you about four products from Seasonic, three of which continue the legendary S12 series: S12-II Bronze (two models with different wattage ratings) and M12-II Bronze. The fourth PSU to be discussed is the first model of the flagship X series called X-750 Gold.
Click the following link for a description of our testing methodology and equipment and a brief explanation of what the specified and tested parameters of power supplies mean: X-bit Labs Presents: Power Supply Units Testing Methodology In-Depth. If you feel overwhelmed with the numbers and terms this review abounds in, refer to that article.
You can also go to our Cases/PSU section to check out reviews of all other PSU models we have tested in our labs.
We will mark the actual power consumption of three system configurations (discussed in our article PC Power Consumption: How Many Watts Do We Need?) in the cross-load diagrams. This will help you see if the tested PSU can meet the requirements of a real-life PC.
Seasonic S12-II Bronze (SS-430GB and SS-520GB), 430 and 520 W
I will start out with the S12-II Bronze series which comes in two wattage ratings. Currently, these are low-end models in Seasonic’s product line-up.
These PSUs come in medium-sized boxes painted black and blue. The name of the series and the wattage rating of the specific product are indicated on the box.
These two PSUs both have the same black case. There is nothing extraordinary in their visual appearance. The case is a standard 140 millimeters long and will suit into any computer case designed for ATX power supplies.
The S12 series does not have detachable cables.
The 430 and 520-watt models differ internally not only in the color and shape of the heatsinks but also in the component layout but turn to have the same circuit design.
As opposed to many modern PSUs, the S12-II series has joint voltage regulation as is indicated by the number of toroidal chokes at the output. PSUs with dedicated voltage regulation have three such chokes (one choke for each of the key voltages: +5, +3.3 and +12 V) but we see only two here. One choke is for the +3.3V regulator and another is shared by the +5V and +12V regulators.
Interestingly, the Seasonic S12 series used to have dedicated voltage regulation but the newer version is simplified in this respect. You will see shortly how this has affected the real characteristics of the product.
KZE series electrolytic capacitors from United Chemi-Con are installed at the PSU’s output. There are also solid-state capacitors there, one for each output line. These capacitors enjoy a good reputation, so you shouldn’t worry about their service life.
Seasonic S12-II 430 W
Seasonic S12-II 520 W
The specified output power of these PSUs agrees with their model names as well as with their effective output power, i.e. if you take into account that modern computers mostly consume from the +12V rail while the combined load on the other rails is but seldom higher than 50 watts. The +12V rail is split into two “virtual” output lines in the S12-II.