Quote Originally Posted by mister_e View Post
yeah sure the on-board USB have a current sensor, not sure if a PCI card have it... if so, how better worst it is? I'll measure it here.

As Darrel says, an external powered USB hub 'may' solve the problem. i don't get your point of auto-detection...

But for sure, there's a current limiting somewhere, XP should warn you in case you overload it.

EDIT: Measurement done here...

My HP machine
Load 5 Ohm..
On board USB - 4.26 volts,
PCI Cards 4.1 volt

My intel machine
On-Board 4 volt
Sir, please see the pdf form Intel titled "Power Delivery Design Issues for Hi-Speed USB on Motherboards" i got it from www.usb.org please try to put the article title on google , you land straight on the location .