Hard drive makes a weird sound every once in a while

[allies]

System specs are in my sig. Running on an Antec TruePower II 550W. Every once in a while my HD (I think my Raptor) makes a weird sound... almost like it powered down and then repowered up. Not really sure what it is. I'm on Vista, but it doesn't sound like the disk is being accessed... it's weird. Any ideas?

 

[cvrefugee]

Vista by default will power down a HDD if not being used, then power it back up when being accessed.

 

[allies]

Really? I did not know this... I guess it makes sense though... it generally happens when I'm not doing something hard disk intensive. Thanks for the heads up. It's just kind of unnerving hearing the noise.

 

[allies]

Actually... I don't know if it is actually the HD powering down and up... I wish I could explain it better. Hmm...