external Hard drive which powers only via USB port

[ranj]

Hi

 

Does anyone know if there are 250gb or above external drives which dont require external power. I conciscious that we are running out of power sockets and I would rather get some external drives which power via USB.

 

are these available?

 

thanks

[localzuk]

The largest I can find is a model by 'Formac' which is 160GB http://www.ebuyer.com/UK/product/127831

[craiglay]

TBH I don't think your going to find one. The only hard disks capable of being entirely powered by the USB bus is going to be laptop 2.5 inch discs. And they currently stop at about 160Gb

 

I have an oldish (40Gb) toshiba laptop hard disk in an enclosure which can be USB powered, however, reading the max power requirements of the disk, it easily exceeds the USB specification. Only some PC's will spin it up, others report a surge and continue if i'm lucky. When its going its ok.

 

Firewire is better for this kind of thing, and seems to be quicker too.

 

Craig

[ranj]

do they do firewire external drives?

[craiglay]

Yeah, here's one, although i'm not sure whether its entirely bus powered, it states it has a power supply.

 

http://www.ebuyer.com/UK/product/127831

 

Craig

[Trav]

I've an external case with 160 gig 2.5" Fuj drive in and it runs on a usb cable with 2 usb plugs on one end, one for power and the other for data I think. Bought the case from ebuyer and the drive from my normal supplier, it works well and is fast for an external drive.

 

BR to all

[Espada]

Just a warning with these. The amount of power supplied is very much dependant upon the machine you are plugging into. I have one of these and it will not work through my USB hub (not host powered) and I get a message popping up saying there has been a surge on the port. It works fine elsewhere though.

 

- What a waste of my 100th post.

[Trav]

No posting can be called a waste!

 

Congrats on your 100th anyway.

 

BR

[Geoff]

Also be aware (I doubt it'll catch anyone out at the moment, but it might in future) that Linux obeys the USB specs rigorously. If a device attempts to pull more power than is allowed by the specs, it'll be disabled. This is done for the health of your motherboard/USB hub.

 

http://lwn.net/Articles/186331/

 

Although the above article deals with Linux. It also specifically mentions mass storage controllers and why trying to 'get away with this' is a bad idea. I suggest everyone reads it.

[Skoggmeiger]

I'm surprised there aren't any devices that can take advantage of using 2 USB ports. 1 to power and 1 for data transfer.

 

Anyone know why this idea shouldn't work? I know it wouldn't be ideal, but I'd settle for it.

[DMcCoy]

You are pulling power from the usb hubs total power output, not the port.

[Busybub]

I'm surprised there aren't any devices that can take advantage of using 2 USB ports. 1 to power and 1 for data transfer.

 

Anyone know why this idea shouldn't work? I know it wouldn't be ideal, but I'd settle for it.

 

There are number of devices which do this, Lacie ones and Thecus enclosures for example.

 

Does anyone know if there are 250gb or above external drives which dont require external power. I conciscious that we are running out of power sockets and I would rather get some external drives which power via USB.

 

Fujitsu recently released a 250gb 2.5inch SATA laptop drive. Bung this into a SATA enclosure and you have a solution. Only problem is that the drive alone will currently set you back over 100 quid.