The combined load capacity of the +5V and +3.3V power rails is low at only 80 watts but, considering that even top-end modern PCs hardly consume even 50 watts from them, it’s okay for a 360W PSU. Also following today’s trends, the PSU can deliver its full output power via the +12V rail, which is the most important power source in modern computers.
The standby source is rated for loads up to 2 amperes. That’s not much but enough for this PSU’s wattage rating.
And we can remind you once again that the Seasonic SSR-360GP complies with the 80 PLUS Gold standard.
Working with our APC SmartUPS SC 620, this PSU was stable at loads up to 360 watts when powered by the mains, but could not switch to the UPS’s batteries even at 280 watts.
Cross-Load Voltage Stability
The manufacturer promises that the voltages vary by 3% or less, and that is indeed so.
The most important +12V voltage fluctuates by 3% at medium loads and by less than 2% at loads above 130 watts.
The +5V rail sports exemplary stability. Its voltage is almost always within 1% and only goes beyond that limit when there’s high load on each of the power rails, which is a rather unrealistic scenario.
The +3.3V voltage is less than 2% off the required level when there's low load on each power rail. At higher loads this voltage is even more stable.
Overall, the Seasonic SSR-360GP is very good in this cross-load stability test.
Output Voltage Ripple
The output voltage ripple is higher than with Seasonic’s more expensive PSUs but fits within the required range by a large margin.
The same goes for the low-frequency ripple: it is just somewhat stronger on the +12V rail but weaker on the +3.3V rail.
Temperature and Noise
The Seasonic SSR-360GP is cooled by a 120mm fan from ADDA. It is the AD1212MB-A70GL model with a rated speed of 2050 RPM.
Although the fan itself produced no unwanted sounds, the honeycomb mesh Seasonic is so proud of (mentioning it on the product box even) presents a bigger obstacle on the way of the air flow than standard wire grids, making the fan audible at 1100 RPM and higher.
Well, the initial speed of the fan is only 550 RPM. It is maintained until about two thirds of the PSU's full output power but then the fan accelerates quickly, which is typical of many Seasonic PSUs. The speed actually triples (from 600 to 1800 RPM) over a 100-watt stretch of loads.
Thus, the Seasonic SSR-360GP is virtually silent at loads up to 250 watts but very loud at loads above 300 watts.
Efficiency and Power Factor
At the reference loads of 20%, 50% and 100%, the Seasonic SSR-360GP is 88.8%, 91.4% and 90.3% efficient, respectively. It reached its peak efficiency of 92.5% at a load of 270 watts.
The power factor is over 99% at high loads, just as promised by the manufacturer.
The standby voltage is highly stable over the specified 2-ampere range.