Seasonic's S12II 500W
The high end of efficiency

Seasonic PSUs aren't particularly prevalent in North America, but the company has a reputation for models with high efficiency and low noise levels. The S12II will have to deliver on both of those fronts to compete with the other PSUs we've rounded up, in part because it's relatively expensive. You can currently find the S12II for sale online for around $110. That's certainly not outrageous for a high-quality power supply, but it's a lot to pay for only 500W of total output capacity.

The S12II doesn't pack a whole lot in terms of extra features, either. Sure you get an 8-pin PCIe connector and plenty of cable length to snake around your system, but the cables aren't modular, and they're not fully sheathed. Warranty coverage tops out at a decidedly average three years, too.

An all-black aesthetic might tip the scales in the S12II's favor, if that sort of thing does it for you. The unit looks quite nice, in an understated sort of way, but a power supply can only have so much visual appeal.

What will be far more important to this PSU's success is just how quietly that 120mm fan spins. Bottom-mounted 120mm fans seem to be the new standard for enthusiast-oriented models, so the S12II will have plenty of similarly equipped competition in its quest for silence.

The S12II starts to justify its price tag when we look at DC output quality. Voltages are consistent across all three load levels. They're also all within 1.3% of ideal values.

Ripple looks very good on the S12II, with all lines averaging AC content around 10 millivolts. These results are consistent across all three load levels.

Seasonic proves its point on the efficiency front, too. The S12II manages over 80% efficiency across the board, peaking at 84% when running at three-quarters capacity.