There are two things I want to complain about. First, there is only one cable with SATA power connectors. If you’ve got a HDD and a DVD drive with SATA interfaces, it would be convenient to use two power cables for them. Second, the cables are awfully impractical. They have thick plastic tubes on (the tubes shine in ultraviolet light and look pretty, but they are just too unwilling to bend) and the connectors have rubber heads. The latter was obviously done to maintain the common color scheme (otherwise, the connectors would be just black), but it becomes a problem when you are trying to plug those connectors in. This may be even impossible if there is not enough space around the connection spot.
The Silent Green complies with the ATX12V 2.0 requirements as concerns the allowable load on the +12V rail – up to 40A. It also has a high load capacity of the +5V rail, though.
Two +12V lines are indicated on the label, but it is actually a single power rail inside the PSU. It is single in every sense of the word because the protection gets disabled if the current exceeds the indicated 20A on either of the +12V lines. Topower calls this an “automatic combining of the lines” but it turns out that the lines were never separate. It is only due to marketing reasons that the label shows two 20A lines instead of a single 40A line. To make this more impressive, the blue LED marked as “Combined” lights up when there is a load of over 20A on any of the lines.
When working together with an APC SmartUPS SC 620, the maximum load power of the PSU was 365W if powered by the mains and 250W if powered by the batteries. This low allowable load (if it is exceeded, the UPS lights up its overload indicator when switching to the batteries or even shuts down altogether) means that the Silent Green may have troubles with UPSes. There is an opinion that all PSUs with active PFC have problems with UPSes, but that’s not true. Most modern PSUs are compatible with any UPS.
The cross-load diagram is not as pretty as the one of the previous models due to the lack of dedicated voltage regulation. Anyway, the result is quite acceptable. The voltages are within allowable limits in a broad range of loads. If installed into a modern high-performance PC, the Silent Green’s +5V voltage is going to be slightly too high and +12V voltage, normal or 1-2% lower than the nominal value.
It’s all right about the output voltage ripple: you can hardly see any pulsation in the oscillogram even at full load. It is much weaker than the allowable maximums.
The PSU doesn’t have low-frequency pulsation on its output.
The PSU is cooled with a 120x120x25mm fan (Globe Fan RL4G S1202512M).
The fan speed is constant at 1100rpm until a load of 200W with something. At max load it is higher than 2200rpm. So, this PSU is average in terms of noisiness. Most users are going to find it acceptable, but it is not exactly quiet. It is inferior to the models from Seasonic and Zalman we have tested in our labs in this respect.
The PSU has 83% efficiency and a power factor of higher than 95%. Both results are far from breaking any records, yet they are good even as today’s PSUs go. Here, the Silent Green differs dramatically from the P7 series that has a hopelessly outdated circuit design.
Although not without shortcomings such as poor compatibility with UPSes, not high stability of the output voltages and very impractical cables, the Silent Green TOP-600SG is overall superior to the TOP-600P7. It is quieter, provides a higher efficiency, and has a very low output voltage ripple (as opposed to the P7 series models that even didn’t meet the requirements of the industry standard to this parameter). It also features active PFC that supports an input voltage range of 90-264V without switches.
