I’ve got as many as six power supply units from Seasonic for this review and they hail from two different worlds. On one hand, there are the expensive top-class ATX units of the X-Gold series with wattage ratings from 560 to 760 watts. And on the other hand, there are compact products for mini-ITX or microATX system cases that are described by the FlexATX, TFX and SFX form-factors and have a wattage rating of no higher than 300 watts.
Unfortunately, compact PSUs are not very popular among enthusiasts. I think they do not really deserve such an attitude because you can build a rather advanced gaming configuration even in a tiny cubic case with a 300W power supply. Yet the fact is that such PSUs are mostly limited to office machines built in slim low-profile enclosures.
Therefore I will not discuss the products in alphabetic order as I usually do. Instead, I will first talk about the more exciting X-Gold series and their junior cousins will follow later on.
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. If you feel overwhelmed with the numbers and terms this review abounds in, refer to the Methodology.
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 X Gold: X-560 (SS-560KM), X-660 (SS-660KM) and X-760 (SS-760KM)
So, the focus of this review is on the X-Gold series from Seasonic, namely the X-560, X-660 and X-760 models. The series consists of six models in total. Besides the three mentioned one, there is a similar 850-watt unit and two fanless products with ratings of 400 and 460 watts. We reviewed one of the fanless X-Gold PSUs earlier (it’s called Seasonic X-400 Fanless SS-400FL) and are going to test the 850W one in the near future.
Curiously enough, the X-Gold series was in fact introduced twice. Last year we tested the Seasonic X-750 (SS-750KM) but soon after its release the company suddenly decided to restart the series. I don’t know the reasons but the fact is that the midrange X-Gold products have grown by 10 watts in their wattage ratings, so the SS-750KM is now transformed into SS-760KM. I don’t think this means something important. Seasonic must have just formally adjusted its product nomenclature for the newer products to be easily distinguishable from the first-wave ones.
The X-Gold power supplies come in black-and-gold boxes with the wattage rating of the particular model being explicitly indicated on its packaging.
The numerous advantages of the product are indicated on the back of its box, namely:
- The DC-DC converters that convert +12 volts into +3.3 and +5 volts reside right on the connector panel, which helps make the voltages somewhat more stable by minimizing the amount of wire and solder connections between the voltage regulators’ outputs and the connectors proper (I can tell you that this component layout is largely due to the manufacturer’s convenience and does not affect the PSU’s consumer properties much);
- Low-resistance gold-plated connectors (the standard gold plating is 3 microinches thick, which is about 76 nanometers, and doesn’t cost much; it is used by many manufacturers but gold-plated connectors are generally the same as nickel-plated ones at work except that the gold plating can indeed protect the pins from burning out at overload);
- High-quality Japan-made capacitors rated for temperatures up to 105°C (I guess there is no computer components maker who doesn’t boast of using such caps);
- Polymer capacitors (this new trend comes from mainboards; such capacitors indeed have a longer service life than ordinary capacitors with liquid electrolyte);
- Multi-GPU technologies support (the PSU just offers the required number of power connectors);
- 5-year warranty (this usually refers to the United States only; in the rest of the world the warranty period may depend on the local laws, the manufacturer’s interest in the local market and other such factors);
- 80+Gold certification (it means the PSU is highly efficient);
- 3-phase fan controller (PSUs generally have two-phase controllers which set the fan at a constant speed until a certain threshold load and increase the speed linearly thereafter. Seasonic adds a third phase: the fan halts altogether at very low loads. I don’t think this makes a difference from a fan that’s working at a very low speed, though);
- High-quality and perfectly balanced Sanyo Denki fans (these are indeed very expensive and very top-quality fans which are superior to ADDA fans that Seasonic usually uses).
The accessories included into the box are not original but sufficient.
There are reusable and single-use cable straps, four screws, a sticker, and a multilingual user guide.