Akasa PowerPlus 650W Power Supply

Interior of the Akasa PowerPlus 650W:

Upon removing the top of the PSU chassis, one can see how tight a fit it is for all the various components. Two extremely large heatsinks engulf not one, but two main transformers (and a smaller transformer typically for 5Vsb and -12V) and a massive capacitor. There is also a huge choke that seems to be dedicated just for the 12V rail, and a smaller choke for the other rails. All in all, this design is quite impressive. Examining the UL registration number points back to Enhance Electronics, a reputable PSU manufacturer with several of their models making the 80 Plus list for their high efficiency. This power supply can even be found on the Enhance website as model ENS-0565.

Examining the PCB mode closely, this PSU does indeed have four (4) 12V rails, that are all fed from a common 12V plane that is all labeled in the picture below. On the top side each 12V pad has its own capacitor and presumably sense circuitry to ensure the 240VA UL safety requirement (also part of EPS specifications). I was unable to examine the top side in any real detail because of how dense everything is packed together, and also blobs of compound were used around all the wires and various components (to prevent them from touching each other and causing a short, among other things). All in all, the design looks quite solid, and to meet EPS12V specifications it would have to be (as their specs are a LOT more strict than the ATX12V "guidelines").

The combine 12V wattage for the PowerPlus 650W model is 504W divided among the four rails! That's more 12V power than some other power supplies have total across all their rails! Because this PSU follows EPS12V specifications the rails are divided up a little differently than one might expect.

• 12V1 - 13A - CPU1 - First 4-pins on the 8-pin EPS12V connector
• 12V2 - 18A - CPU2 - Last 4-pins on the EPS12V, and the SATA cables
• 12V3 - 16A - 24-pin connector, PCIe connectors, and Super Micro AGP connector
• 12V4 - 8A - All the 4-pin molex connectors

If you refer to the table below, notice how the 3.3V and 5V rails are still pretty normal capacities with most of the power dedicated to the 12V rails (as it should be). Most modern computers use the 12V rail for all the primary power needs of the main components, i.e. the CPU(s), motherboard, and Video Card(s).