Seasonic's S12 Energy+ ATX power supply has a large array of connectors that make it perfect for an enthusiast PC.
It has two PCI Express power connectors to facilitate a high-end SLI or CrossFire graphics card setup, six Serial ATA connectors and nine regular connectors for older hard drives and optical drives.
The S12 Energy+ is capable of accepting 240V from a wall outlet, which is significant as most supplies that we have seen (such at the 630W Thermaltake) are rated only at 230V. This means that the supply won't be stressed by the AC voltage coming into it as it's designed to handle it. As a result, it will run cooler.
The S12 has a 12cm ball-bearing fan which was very quiet during testing. The supply also has fairly small dimensions (15cm x 14 x 8.6) compared to other 500W and 600W supplies. The total output capacity of the S12 Energy+ is 650W from its 3.3V, 5V, 12V and -12V lines, but it's the sustainable voltage on the 12V lines that is most important as it is these lines that provide power to the CPU, graphics card, drives and fans. Four parallel 12V lines are present in the S12 Energy+, all capable of supplying a total of 52A of current. The parallel 12V lines are used to spread the load across the system in order to provide a more stable supply of power. We tested the 12V line that was connected to our drives with a digital multimeter and by running a benchmark (SPECviewperf) to ensure the CPU was drawing plenty of power. The voltage reported back to us was 12.15V, which did not fluctuate. When the CPU was idle and with only one drive connected to the 12V line, it only went up to 12.16V. It was indeed very stable.
VERDICT: Users looking for a high-end supply should put the Seasonic S12 Energy+ at the top of the shopping list.