USB hard drive enclosure -- power supply or no?

[enclosure]

I need an enclosure for my 200 GB 3.5" drive. I looked at some on Newegg, not sure whether I need the kind with an external power supply or not. I won't need to use the drive when the laptop's not plugged in; can I just power it off the USB port?

Thanks!

 

[zephyrprime]

nope. Some 2.5" can but not 3.5.

 

[Mday]

You cannot power any 3.5" drive from a laptop without heavy modifications to the laptop. The logic runs at 5V, but the motor\actuator runs at 12V.

You cannot power any 2.5" drive from one USB port. There are 2.5" drive enclosures that will allow you to power the drive off of a 2nd usb port or a ps2 port.

USB and PS2 both power devices with 5VDC.

 

[enclosure]

I've got an old 2.5" 5400 RPM 4 GB Travelstar that I run in a cheapo plastic USB enclosure off one USB port w/o a power supply, no problem.

But maybe the power needs of the big drive are too much for that. So the next question is: fan or no fan? It looks like most cases have no fan (except the Thermaltake SilverRiver); I'm guessing that means I don't need one. Anybody have better information?

 

[beatle]

I run a 6 gig, 4200 rpm Travelstar from one USB port. No issues.

 

[akira34]

Originally posted by: Mday
You cannot power any 3.5" drive from a laptop without heavy modifications to the laptop. The logic runs at 5V, but the motor\actuator runs at 12V.

You cannot power any 2.5" drive from one USB port. There are 2.5" drive enclosures that will allow you to power the drive off of a 2nd usb port or a ps2 port.

USB and PS2 both power devices with 5VDC.

First part correct, probably.
Second part dead wrong...

I have three external hard drives using the 2.5" drive inside and they have no problem at all running off of my tower's USB port without any extra power. I've also powered those same drives off of different laptops using just one port. Some laptops don't provide enough juice to the USB ports to power the drives (but more than enough for thumb drives). The drives (and enclosures) only draw 5V with ~.4A worth of power.

Next time, you might want to check your facts before saying the mobile products won't work, or making blanket statements that are so obviously false.

 

[Mday]

Originally posted by: enclosure
I've got an old 2.5" 5400 RPM 4 GB Travelstar that I run in a cheapo plastic USB enclosure off one USB port w/o a power supply, no problem.

But maybe the power needs of the big drive are too much for that. So the next question is: fan or no fan? It looks like most cases have no fan (except the Thermaltake SilverRiver); I'm guessing that means I don't need one. Anybody have better information?

I have an enclosure with a fan, and one without for 2 3.5" drives. The one without works fine, but it does get really hot. It depends on what you want to do I suppose.

As for Akira's comment... you are a very hostile person.

 

[akira34]

Mday, if you think I'm a "very hostile person" you'll never make it in the real world... People that make statements about something not working across the board, but there is easy to find information to prove them wrong get no sympathy from me.

Laptop drive enclosures are MADE to be mobile and not need additional power. Enclosures for 3.5" drives are [typically] used when in an office/home setting where mobility is not top of the list. I do recall seeing one or two enclosures listed that drew all their power from the connection. I've never had one of those, so I can't say if they are any good or not. Personally, I'd rather have a power block to plug in for power on the desktop drive enclosures. Especially when it's easy to put a 300GB drive into one of those now. Of course, other companies offer up external drives in up to 1.6TB, but good luck in trying to make one yourself.

 

[Zepper]

As mentioned above, 3.5" drives need 12V for motor and/or head drive. There is no external source of 12V on any laptop that I know of. Notebook drives (2.5") run entirely from 5V (the main reason they are so much slower than desktop drives) so at least some if not all can run from the 5V supplied by USB or PS/2 - personally I'd run both of them off external power (I've rigged a special battery pack just for such uses) whenever possible. No sense putting unnecessary load on those low power connections...
.bh.

There's the :sun: !

 

[akira34]

What did you use for the battery pack??? I've only experienced issues on a handful of laptops not giving enough power over the USB2 port... Any that have a 6 pin FireWire connection have no issue providing more than enough power for the hard drives I have. If the battery pack was fairly easy to construct, let us know (or email me about it)... It would be nice to not need to add another cable on the occasions when the USB2 port isn't enough... Luckily, only one of my enclosers is only USB2. The other two mobile drives also have FireWire, which means I get to just plug and play with them.