Hi guys, I've just installed another 460 in my system, and when I've run Furmark I got an odd whining/chirping sound, I'm pretty sure its harmless capacitor whine/coil whine but one of the possibilities I considered was that one of my cards was trying to draw more power than was available. The reason I thought that was when Furmark was running one of the cards showed it was running at 99% gpu load and the other 93%. I'm pretty sure its enough but I thought I'd get some other opinions. I'm thinking of overclocking at some point and I believe that can draw up to 50W more than stock clocks. My PSU is the 750W Truepower New, are others here running similar rigs? Do I need more power(URG URG URG)or am I being a bit paranoid?

I thought an 850w Seasonic was enough to power 2x5870 and it wasn't, was even told it would be enough but I guess I got a lemon PSU. Powers one 5870 fine but not two. I put in a 1000w Mushkin PSU and that powers them both fine.

650W is all AMD requires for 2x HD5870 CrossFire. Probably, that's enough for 2x GTX460. Hopefully, the Nvidia site should give the power requirement -- as should the "instructions" that came with the GPU.

The best PSUs are "single rail". Some power supplies are "multi-rail". The power is split among multiple 12V rails (almost like separate PSUs in one box adding up to 750 -- but much less individually). In some cases, too many items plugged into the same rail over stresses that rail. Just a thought. Something to check, if one thinks one has a problem.

I run a 700W Thermaltake, and it handles my two 5870s and my overclocked i7 920 just fine.

I think Seasonic put out a batch of flaky S12-850w PSUs when I bought mine because the first one wouldn't even turn on, just kept tripping over. RMA that one and the replacement worked fine until I went with 2x5870, that one kept tripping over exactly the same as the first one.
I could send it back to Seasonic but not worth the effort so just got the Mushkin on sale for $99.00 instead. That one has a switch for either single rail or multiple rails and it works fine in both modes so I use it as multiple rails because that is safer. The only reason they ever went to multiple rails is because Intel recommended it due to safety concerns.

The thing that irks me is people trash talk Mushkin PSU because it is made by Topower and rave about Seasonic (use by Corsair and others) and yet the Mushkin is obviously better than the Seasonics I got. Plus 1000w for $99.00 is a very good deal because at the time a comparable Corsair 1000w was well over $200.00 CAD.

Thanks for your answers guys, I'm tending towards the idea that it is the graphics card making the sound. They're so close together its hard to tell. I'll do a bit of component swapping on Saturday and solve this once and for all. Antec seem to be confident that this psu can run 480's in SLI, plus the EVGA 460 is the newest component in my build so surely the most likely candidate for the whiney sound.

My GTX 560ti does something similar; especially in game menus or older games where my FPS skyrockets and the card "whines" from the extreme frequencies. I usually force on Vsync which seems to help because it can get annoying even tho it's not very loud

Exactly that, when I'm in the menu screen for Empire TW it hits over 1000 frames ps. Turn on vsync and the sound stops. It's similar with BfBC2 although the sound doesn't completely disappear with that one, largely but not completely.