Seasonic SSR-360GP: Measurements
Efficiency According to the 80 PLUS Spec
Efficiency by Load
Proudly displaying the 80 PLUS Gold logo on its box, Seasonic's SSR-360GP has something that no other power supply in our two-part round-up offers, and we're eager to test it. The efficiency requirements are significantly higher for a Gold-certified PSU than the Bronze-rated ones. For all three load scenarios, the efficiency minimums to qualify for 80 PLUS Gold are five percentage points higher, in fact. And Seasonic's SSR-360GP satisfies those stringent requirements without a problem. At 20% and 50% of its maximum load, the supply complies with little leeway to spare, while its efficiency at full load is noticeably better than the Gold tier's requirement. Seasonic extends its 5% advantage over the other PSUs even into low-load conditions. At 25 W, its efficiency is an admirable 75%.
The scope picture again reveals spikes that seem to plague all of the lower-end PSUs in our round-up. If we take them into account, all of Seasonic's DC rails would violate the ATX spec. But because we're looking past them, the waveforms look OK, if not a little more jagged than we'd expect. The SSR-360GP passes all other tests without a problem. It is also barely audible. We measured 30.2 dB(A) at 40 W and 30.6 dB(A) at 200 W; you'd only hear that with an ear close to the power supply.
A Close Look at the PCB
Building an 80 PLUS Gold-rated PSU to sell at $60 is quite a challenge, even for a company like Seasonic, since the high-quality parts are more expensive. Thus, money has to be saved elsewhere. For instance, we notice that the SSR-360GP's soldering quality, while OK, does not approach what you'd find on the company's flagship X-series. However, the electrical design is still quite modern, utilizing a DC-DC converter and an LLC resonance converter. Almost all capacitors are made in Japan. We found capacitors from Hitachi, Chemi-Con, and Rubycon. A few capacitors are made by Korea-based Enesol. All necessary components are there, and the component layout looks nice.