5400 vs 7200rpm HD external enclosure power requirements?

[sprime1]

I'm looking at purchasing a 2.5" hard drive and an external enclosure. The main feature i want is not having to use an AC adapter or a second USB port to power the drive.

Is there any evidence or research done to tell us, say that 5400 vs 7200rpm hard-drives require less power, so they don't need a secondary power supply?

For example, most 2.5" external hard-drives, like the WD Passport series, only require the 1 USB connection for power and data. How do i mimic this single USB connection with a bare-bone 2.5" drive and an aftermarket 2.5" enclosure??

Much Thanks!!

 

[cube]

FireWire provides more power than USB.

 

[cluthz]

If you are going the USB2.0 route there will be no benefits with 7200RPM over 5400RPM.

 

[cube]

I can power the Momentus XT in the OWC AL mini from FireWire.

 

[sprime1]

Firewire is not an option for me unfortunately. The main purpose of this new drive is to plug it into the USB port on my TV to watch movies. I currently have a 500gb WD Passport harddrive that is full, and requires no secondary power source. I'm looking to replicate this.

 

[cluthz]

The controller from my two year old WD Passport (was a 320GB) can power a Seagate Momentus XT.
I put mine in the enclosure when I transfered users from the internal HD on my MBP.
How much power the aftermarket enclosure provides should be about the same I guess and the WD Passport had a 320GB Scorpio Blue.

No guarantees but I guess it should work the same way.