So I was trying to fix a bad router with a firmware upgrade a few days ago and at one point shut down my computer. When I turned it back on, it didn't. I pressed the power button and all the lights that are supposed to come on came on, but only for a moment. My heart sank. I've fried another power supply. The last time this happened, there was a clear and obvious stimulus - the power browned out and my shitty, older than dirt PSU couldn't hack it. So the guy at the store replaced it with a Raidmax (I later learned how terrible an insult this was). I plugged the whole thing into an APC Line-R Voltage Regulator (1200VA) in order to prevent this from happening again. Only it seems to have happened again.
Sick and tired of PSU trouble, I bought a Corsair TX750W. I run an ASUS M3N78 Pro motherboard with a Phenom II 920 quad core processor and an ATI HD5770 (why am I running an ATI Vid card on an Nvidia-intended mother board? I had a GeForce 7950GT when I bought it).
I want an absolutely rock-solid system that does not have the suicidal tendencies my last power supply had.
1) I got the TX because they were out of HX. Should I go back and exchange it, or will the TX still be overkill for my needs?
2) Would it help if I regularly slaughtered small woodland creatures in the name of Thor?
1) The TX 750 is a very good unit and probably far more than you need. The only thing the HX series really brings you are modular cables (ability to remove ones you don't need). I see no reason to exchange it.
2) Probably not. Especially not if you don't want PETA showing up at your door
1) ... I wouldn't exchange the TX unless couldn't get good cable management and it was causing heat issues. Than and only than would I exchange for the HX. Yes, the HX is better but the TX is good, so why go through the hassle. Also, it is a little overkill for your system but I've seen people waiting to put 1000W PSU in systems in like yours... Now that is OVERKILL!!
750w is definitely overkill. 450w would be plenty for one 5770, 550w would be plenty for two.
1) The only thing the HX series really brings you are modular cables (ability to remove ones you don't need).
The 750HX isn't just a 750TX with modular cables, it's built on a completely different platform that has better voltage regulation, ripple suppression, and efficiency. Not that the TX is bad, it's very good in fact, the HX just happens to be one of the best 750w PSUs on the market(along with the Seasonic X-750 and XFX 750w BE) and is priced accordingly.