I guess your card could be throttling because of it (and giving you lower FPS). More likely, however, it isn't affecting FPS at all and you've just gotten lucky that it hasn't crashed. Essentially, those readings are saying that your power supply isn't getting the voltage it should be (about 40% less!!!) on the most important line (12V). If your components ever needed more than 7V * (whatever amperage they're pulling), your game/PC would crash (and possibly cause damage to a component). You're probably only drawing 400-500w with your system, so you haven't hit that ceiling yet.
Like I said, though, I would turn it off until you can replace the unit.
Corsair is usually a good bang-for-your-buck. EVGA has been cranking out good PSUs. Seasonic is excellent. Just search for reviews or ask here about a particular unit.
You shouldn't need more than 550w, by the way.