Corsair 1200W Modular PSU
MSI Twin Frozr III Radeon 6970 (slightly OC'd)
Intel i5-2500k (OC 4.5Ghz)
Corsair H60 CPU Cooler
Scythe Gentle Typhoon 1850RPM push-pull
ASUS P67 Sabertooth Motherboard
8GB (2x4GB) Corsair Vengeance RAM
Raven RV02-E Case
If I left anything else out that you want to know, feel free to ask.
THE ISSUE: Picture me, all excited to put together the computer I saved up for nearly two years to buy, only to realize, to my dismay, that the PSU gives off a whine when I started using the system.
No problem though, I went online and looked up potential fixes. I tried them all--disabling power saving options, disabling SpeedStep and C1E, updating the BIOS (which I naturally had to do anyway), the whole 9 yards--no dice. I still get the slightly audible but really annoying whine.
After reading up on this extensively, I came to the conclusion that it was a faulty unit with coil whine, but now I'm not too sure--I've noticed a certain pattern copping up: the noise sometimes vanishes when the computer is drawing a lot of power. I say "sometimes" because unfortunately I just noticed this trend, so I haven't really documented it well yet.
I just finished about an hour of playing Assassin's Creed II at full graphics and 5760x1080 resolution. I had my headphones on at the time, but when I took them off I noticed that my computer was unusually quiet--I put my ear against the power supply, and realized that the noise was gone. All I could hear was the slight whirr of the fan. There was no coil whine at all! However, as of writing right now, the whine is back (after about 5 minutes idle).
I actually observed this once or twice in the past when I was running the computer through Prime95 stress tests. I woke up one morning after running the test for 8 hours, and noticed that the sound was gone! I was naturally very happy, but later, after I ended the test, the noise started up again.
A friend of mine, someone I really trust to know his stuff for computer building, told me that there's a possibility my PSU is actually operating outside of its ideal range when I'm at idle. This would explain why the noise goes away after I start drawing large amounts of power from it, i.e. running a graphics intensive game at high settings and high resolution. If this was the case, then spending money on getting an RMA from Corsair (the $300+ hold on my account, the expensive shipping) would be pointless, since it's not an issue with the PSU but an issue of my system as a whole). Instead, he suggested that I simply bump the second MSI 6970 I had planned on buying into a higher spot on my buy-list. Once installed, he said it should boost my power consumption another 100W or so, and well into the 1200AX's optimal range.
Do you think this might be the solution? Would you recommend I get an RMA?
Update: I ran a quick few minutes of Furmark (a GPU stress tester) and from the moment the test started, the PSU noise ramped up :\ The noise itself is high-pitched, slightly stuttery (it's very high frequency) and sort of sounds like the noise you'd hear from the backs of old TVs. It's not particularly loud, but it is very audible because of the high pitch.
Your system would run fine on a 600watt PSU so 1200watt is a little excessive but it should not whine any way so I will have to say RMA would be in order if you are sure it is the PSU not one of your fans!