Specifications

The Twins 500 W actually consists of two modules and the main chassis (frame). Each modules can deliver up to 520 W of power on its +12V rail, but the frame with both modules installed is only capable of 500 W. Both modules also operate in parallel, while only one such module is kept operational with PSUs for servers, with the other in standby mode, ready to take over should the main module fail.

For those of you wondering why FSP chose to keep both modules operating, which to a degree compromises the reliability of their redundant PSU, and why its maximum power output is 20 W less than that of its modules, there is a rather simple explanation: While server units don't need to be fed with 5V and 3.3V, desktop PCs still utilize those rails. So in order to use server-type modules like those for the Twins 500 W, there has to be a way to generate the required minor rails. In the Twins 500 W, the frame houses the DC-DC converters that generate the minor rails, so both modules are required should the frame need to deliver a lot of power on the +12V and minor rails at the same time.


The specifications on paper mention three +12V rails with 16 A maximum current output each; however, our tests show that OCP is configured much higher on those rails. The minor rails are quite strong for a 500 W PSU, while the 5VSB rail is set to 3A on papers even though our tests show it to produce more than 10 A!

Cables & Connectors, Power Distribution

All cables are affixed, and since this is a server-like PSU, there are two EPS connectors. The number of PCIe connectors is restricted to two, while the number of SATA connectors is adequate. There are only 4-pin Molex connectors, though, installed on a cable that also hosts a pair of SATA connectors.


Power distribution looks good given the restricted number of +12V rails. Moreover, the very high OCP triggering levels significantly restrict the importance of power distribution.