The high-frequency ripple of the output voltages proved to be low even at full load.
It is accompanied with low-frequency ripple at the double mains frequency, i.e. at 100Hz in this case, but the total ripple doesn’t violate the permissible limits and the PSU complies with the requirements in this respect.
The cross-load diagram doesn’t look so good. The +12V voltage depends on the load and sags heavily when the load is high. On the other hand, all the three voltages are going to be close to their nominal values in a PC with a total consumption, for example, of 200W in which 160W falls on the +12V rail.
The PSU is cooled by an 80x80x25mm fan (Adda AD0812MS-A70GL). Adda fans have earned a good reputation. Products from that firm are used even in the quietest of PSUs.
The speed adjustment range is as small as 10% which indicates a greatly simplified fan controller. Anyway, the fan is high quality and not very fast, making the PSU rather quiet at work – you can only hear the hiss of the air flow.
The A300M-C heats up a lot. The difference in the air temperature exceeds 10°C and I could feel the characteristic smell of hot insulation when the PSU was working at full load. It passed the test without failure, though.
The PSU is only 77% efficient. The circuit design which dates back to FSP Group’s very first ATX12V 2.0 series is becoming outdated. The power factor doesn’t make it to 0.6 in a broad range of loads. Such PSUs won’t be a good choice for an office with many machines as they “pollute” the supply mains greatly.
In fact, the Tsunami Hercules A300M-C is an entry-level PSU for low-end PCs with a power consumption of 150W and less (considering the reduced consumption of modern dual-core CPUs, this number can accommodate a rather advanced graphics card even). It will satisfy you with its stable and rather quiet operation under such conditions.
On the downside, the PSU has very short cables, being obviously meant for microATX system cases, and a very low power factor. The power factor is unimportant for a home user, but can create a considerable extra load on the electric mains in an office with a lot of PCs.
Tsunami is selling the Hercules PSN-300P alongside the Hercules A300M-C.
Although it comes in the same box as the A300M-C (some marks on the side panel are different), this PSU has nothing to do with FSP Group and even with the ATX12V 2.0 standard. Take note that its maximum allowable load on the +12V rail is only 168W, i.e. almost 100W lower than that of the A300M-C.
I didn’t test the Hercules PSN-300P model and cannot tell you about its real characteristics and quality. But if you want to purchase a PSU manufactured by FSP Group, you should make sure the label contains the right model name.