Seasonic has been around for a long time-since 1975. It is more well-known for its OEM line of power supply units, but it sells some models retail, as well. It touts the S12D 850W power supply unit as being certified 80PLUS Silver, proving that the unit is at least 85% efficient. Seasonic claims that the unit can achieve 90% efficiency! Add that with a five year warranty and a nearly silent fan and this is one unit worth seriously considering. ThinkComputers has the review.