AX860i loud, high-pitched beep under load

[riscorpian]

*EDIT: Please disregard. The cause was actually the UPS in which my system was plugged, not the PSU (which is an anagram of UPS, not that it really matters at all; I just thought that was kinda cool). Please ignore this thread. I'm a moron.

 

I've searched around these forums and the Internet in general for info on the bizarre noises the AXi power supplies can produce, but I don't really see anything relating to this particular type of noise. If I missed something, please feel free to point it out.

 

A few days ago, I used the government's money (tax refund) to buy two RHD7970's and an AX860i to power them. All was well until I fired up Crysis 3 and started hearing a loud, high-pitched constant beep during the more graphic-intensive scenes (i.e. 99.9997% of the game). However, I did notice that the beep stopped when I turned to look at a wall or something with less detail. After a minute or so, I started to notice graphical glitches, so I closed the game and killed the overclock I had on the cards. That seemed to fix everything. But then, I downloaded the Unigine Heaven benchmark and tried again. Revenge of the beep. Even on the stock clock of the cards, it only took about a minute before that beep was back.

 

Naturally, I assumed it was something with one of the cards, but I'm not so sure anymore. I genuinely couldn't tell what the source of the beep actually was. It's definitely something in the lower half of my case, so it could be either the PSU or the cards. I did some extensive testing on each of the cards in question, and as far as I can tell, both of them are A-OK. They ate that benchmark for lunch on their own, and they both performed about equally as well. That beep only shows up when they're on a crossfire.

 

According to Corsair Link, I'm never exceeding 500W on the PSU. With the stock clocks, I wasn't stretching far past 450. I did notice that the beep seemed to show up at around the point where I hit 450 though.

 

Here's how I have it wired: Image here (I don't have a smaller size for it, so I'm just linking it). I used both of the dual PCIe cables to wire each one. In that image, I used one plug of each on both cards. I've since switched to one cable per card so both plugs are in both of the ports on each individual card. That didn't make any difference at all. The only other PCIe cables I have left are the two with only one port on them. I have not yet tried those.

 

I'm simply looking for ideas of what else I can try in my effort to narrow down this problem. That beep sounds like a warning beep, as if something is overheating. But, at least according to Link, all temperatures are fine. At first, I thought maybe the PSU fan wasn't working, but it definitely is. I just can't see anything at all that would cause something like this. What's going on here? The PSU is the only thing I haven't really tested yet, but I'm not quite sure how to do that. What are my options at this point? What else can I try?