[ltp] any successes with 2.5 inch laptop-IDE-drive USB enclosures?

[Richard Neill]

Tino Keitel wrote:
> On Wed, Mar 26, 2008 at 12:40:59 -0600, Pablo Vera wrote:
>> Since the 2.5 enclosures draw power from the USB port, I've found that  
>> sometimes one USB port is not enough to power up the drive, in which  
>> case I get a lot of errors.  Some enclosures come with a Y split cable  
>> so that you can plug it into two USB ports.  In this manner the  
>> enclosure will have double the power and will be able to power up the 
>> drive.
>>
>> Does your enclosure has a Y split cable ?, what is the power rating for  
>> the drive ?
>>
>> One USB port = 500 mA
>> Two USB ports = 1000 mA = 1 Amp
> 
> AFAIK the limit is per hub, not per port. So as long as both ports are
> on the same hub, you don't get a higher limit

However, doesn't a typical motherboard have 8 root devices, and a 
typical thinkpad have 3 root devices?  Thus, each port on the computer 
itself is capable of providing the full 500mA.

Also, what actually happens if you overload the port a bit? The spec 
says you are only "permitted" to draw 500mA, but there doesn't seem to 
be any way to enforce it.

That said, I once managed to short out the USB port of my thinkpad, 
while experimenting. No permanent harm was done, but the machine 
instantly crashed.

Richard