



Seagate, the manufacture of the drives, makes two models of the Momentus 500GB 7200RPM drive. The one installed in the 17" MacBook Pro (ST9500420ASG) has a G-Force protection system built into it to help prevent damage to the drive from shock. Some people, including myself, surmise that there may be some incompatibly between the drive and the anti-shock technology that is built into the MacBook Pro. I recently installed a Seagate Momentus 500GB 7200RPM drive (ST9500420AS) without the G-Force technology in my 15" 2008 aluminum MacBook Pro and have not had any problems.
Apple has not made any comment regarding the sound and performance issues, but people have been reporting that Apple is exchanging units without any questions.
If you are experiencing problems with your 17" MacBook Pro with a 500GB 7200RPM drive installed, let us know about it here.
Below are some YouTube demonstrations of the sound.
UPDATE: Try this workaround reported by Hardmac: Stop the beeps with the 7200 rpm hard disks of the MacBook Pro



