The range-topping Seasonic SS-1200XP3 offers a capacity of 1200 W, a fully modular design, and an 80 Plus Platinum certification that provides 92 percent efficiency at 115 Vac and 50 percent efficiency while under load.
The SS-1200XP3 also shares a number of features with other P-series PSUs including a semi-fanless operation whereby the Sanyo Denki San Ace 9S cooling fan is only engaged at loads of 30 percent or greater and 105°C rated Japanese capacitors.
Though this hasn’t been confirmed, we expect the SS-1200XP3 to contain a quad-rail design that is similar to its predecessors. We're not entirely sure why Seasonic has continued to advertise the P-Series as only having a single +12V rail.