What is the best psu for haswell's c6/c7 low-power states?

Okay so I got a new haswell based system and I've been having a problem with the psu I have. It makes the oddest noises and it hasn't let up for over a week and something. I was told it was it's fan and I've also been told that it's normal and that it'll go away and I've also been told that it's a sign that it's about to go out. I'm really willing to just wait it out and see if it'll go away. Now I don't know if it would have anything to do with haswell's low power states or not but I just thought I'd ask what psu would be the best for that. I'm also running a gtx 780 so I would like something in and around the 750w range. I need a reply ASAP cause I'm hoping to go buy a new psu today and there for if you could give me maybe like 5 different psu's that would be good, that would be awesome. Thanks in advance.

can you upload either a video or sound file of the sound it's making? Is it more of a ticking (fan) or a whine?

Are you only powering a single 780? If so, considering you're on Haswell, you will never use 750W. You probably won't use more than 350W, 400W max, with heavy overclocks at full load.

The C6/C7 sleep states are kind of annoying; most PSUs worth buying today, even if they're not actually rated for C6/C7 sleep states, are capable of going that low of wattage, perfectly safely. I'd get a Seasonic G series PSU, either the 360, or 450 (550 if you cant find the others). Even if you put another 780 in there, a 550W PSU would be fine.

 

it's like a high pitch noise and then just last night it made a groaning or moaning noise. It's hard to explain but all I know is that it didn't sound normal. I'll still RMA it so all I really need to know is what one should I replace it with. Oh and if you really wanna try and hear the noise I'd be willing to do a skype call.

I only have one 780 and it was said to need a min of 600w.

 

Because they're protecting their own asses in case some newbie uses some cheapo PSU and blows his system up...

If it's 80+ gold, you can stay below the recomended wattage. (Within reason of course!!)

Well I actually already got another one and apparently it WASN"T the psu..... Well at least I can use one as a paper wight lol. I still hear the noise though and I'm not sure what to do now. And yes I was stupid and bought another 750w lol. Oh well I guess I'll just end up using it for more then one build.