Large cursor and video driver crash issue was fixed for me with a gigabyte ud4p bios update. Haven't tried the heaven dx11 benchmark since then though.
I was going to say it's the "not enough power" alarm*, but your sound is relatively quiet in comparison.
*I accidentally forgot to plug in the PCI-E power connectors when I first installed my 5850. The card let me and my neighbors know that it needed more power. Most high pitched noise out of a...
http://www.engadget.com/2009/10/31/iphone-and-windows-7-dont-play-nice-intel-p55-chipset-to-blame/
I ahve the same issue. I'm sure it will be fixed though :)