Digital My Book Essential -> does it turns on and off with my pc/mac automatically?

Dear All, I would like to buy a 2GB Western Digital My Book Essential (WDBACW0020HBK) []. Is this product having the “GreenPower Technology” same as My Book for Mac (WDBAAG0020HCH) []? I mean has the My Book Essential the power-saving feature turns the drive on and off with my pc/mac? Thank you for your answer, dk

This an external drive so the internal drive features do not apply

the drive does have a software that enables sleep mode after a certain time

the drive will turn off and on regardless of the feature… This is more of a sleep/awake sort of thing