I have the GX 650W power supply, my room is averaging around 20C to 24C so it's not boiling, and even so at idle it sounds like it's the loudest part of my rig in gaming it sounds like a bloody wood grinder! Thinking if it's worth it getting a corsair or something like the Be Quiet Pure Power 630W.
I've heard the GX series does that. I personally would have gone for the HX 650, it's 80+ Gold and very well built. If you're looking to replace, I would def go with that one, or a larger one in the HX series if you plan on adding another GPU soon.