Under the Hood
Here are a few pictures showing the layout and components inside the EVGA SuperNOVA 550GS and 650GS Gold power supplies. Internally the two units are nearly identical (except for a couple larger/additional components in the 650GS) as you would expect as they are both built upon the same platform. EVGA is using Seasonic as the OEM for the GS power supplies.
The new GS series features a modern design and the layout of components is clean while the soldering appears to be very good. Two DC-to-DC converters are used on the secondary (located behind the silver AC filter section can) to produce the +3.3V and +5V minor rails from the +12V main section.
All of the capacitors used inside the new 550GS and 650GS PSUs are high-quality Japanese electrolytics along with solid polymer caps on the secondary. The 650GS incorporates a single Nippon Chemi-Con primary capacitor rated for 560 uF, 420V and 105°C. Looking good.