|Did you look at the specs?|
single 120-140mm cooling fan? - yes, ultra quiet 120mm double ball-bearing thermally controlled fan
active PFC? - yes
80 plus efficiency? - yes, 80 PLUS Certified. Efficieny of up to 85%
single +12v rail of 30A or better? - yes, +12V@41A
decent warranty (3 yrs or better)? - yes, 5 years limited warranty
Do you need a 550W unit? Probably not.