General Mac OS X Discussion General Apple and Mac OS X Discussion
| ||Thread Tools||Display Modes|
Join Date: Feb 2009
Re: USB DRAWING TOO MUCH POWER?? WTF - 04-26-2009, 11:27 PM
Yeah the weird part is that it worked perfectly fine plenty of times. This is a USB powered HDD and it also has a port where you can plug it to the wall. I'm missing that plug and I was hoping it would piggy back it for the initial connection. I have to look around for one. I guess.
Join Date: Mar 2009
Re: USB DRAWING TOO MUCH POWER?? WTF - 04-27-2009, 12:47 AM
The USB spec says the most 1 port may provide is 500ma (.5 amp). Some/Many PCs (especially older ones) were designed sloppily and were happy to deliver more current on 1 port as long as the total current delivered to all ports didn't exceed .5 times port count. Macs were always designed with a limit per port. Many older drives need just over 500ma to startup (generally running doesn't need much). Many more PCs exist than Macs. So hardware manufacturers were quite happy to build a USB powered drive that needs more than 500 ma and didn't give it a second thought. Newer laptops of all kinds are increasingly enforcing the spec (for better power management and battery life) so some manufacturers are better about making their drives. Seagate passport drives, the older ones built around older PATA drives are notorious for this but their newer drives based on the newer SATA mechanisms don't. Other manufacturers routinely box their drive with a dual headed cable (one is a standard USB connector and the other just has the power pins connected).
You can purchase a 2 to 1 USB cable to get your drive to work like this http://www.eworldsale.com/cables-to-...986_26851.html Or a hub like this http://cgi.ebay.com/High-Speed-USB-2...%3A1|294%3A200
Copyright © 2008-2016 MyDellMini.com.