Interesting USB Charging Behavior

[jeigh]

I have a Dell Precision m4400 and was using Win7 since I received it. Of course, I wasn't able to make full use of the USB charging capabilities for what I thought were low-power USB ports.

I recently decided to try installing OS X on it. Works great but one thing definitely caught my attention - full-power USB charging! I've now installed VMWare Fusion and noticed that if I pass control of the USB ports and iPad over to my Win7 VM box it goes back to the slower trickle charge.

Has anybody else noticed this behavior? Particularly, I'd be interested in those with genuine Macs who Boot Camp into Windows. Do you have full-power charging capabilities in Windows or just while in OS X?

OS X

Win7 (Virtualized in OS X)

 

[al256]

Holy crap! You're right. I just booted into Vista on my current gen iMac and yes indeed, my iPad is displaying the 'Not Charging' message. Yes of course, this is directly plugged into the computer.

 

[fehhkk]

Seems like an OS X "feature" to me

I'll try it on my Hackintosh...

 

[jeigh]

Thanks for verifying.

So it sounds like this is at least also partially related to the USB drivers in Windows and not solely being a high-power/low-power USB bus issue. If so, it seems like there's at least some of us with high-power USB ports that we aren't able to take advantage of.