HDD Power Question.

What determines how much power an internal hard drive requires: capacity, number of plates, connection type? Is there any way to see how much a hdd pulls?

 

Check the specs before you buy. Some will show how much power is drawn.

 

All hard drives, whether IDE, SATA or SCSI connect to power from the 12 volt rail of your powersupply. How many watts they draw varies by manufacturer as well as the condition of the drive. In otherwords a hard drive thats having trouble spinning because of bearing failure will draw more watts because the motor is struggling to turn the platters. I believe the average watt draw of an internal HDD is around 2-3 watts when its running and around 5 watts to spin up from a dead stop.