usb device

[Bobman88]

Hi all,

Each usb port at root hub can draw max 500mA power.

Q1 : If I have a secondary 4 ports usb hub -bus powered, is there any power
limitation on each port, or just each port not exceed 500mA and total not
exceed 500mA ?

Q2 : On a self-power sec usb hub, will there be sure a problem when total
power draw may exceed 500mA, but some device may idle while others is in use
?

Q3 : If I have a secondary 4 ports usb hub - self powered, can each port
draw up to 500mA power ?

Q4 : My desktop is usb 2.0 compliant, is that mean I can have up to 8 root
hubs ? I just find 6 usb ports on my box.

thanks a lot.

 

[Bob I]

500mA is the technical specification. What happens with any particular
piece of hardware is a manufacturing issue. Windows only uses what is
provided.