USB 2.0 bandwidth question

[sneskid]

Most motherboards these days come with 4 USB 2.0 posts on the back. The USB 2.0 speed is ~57MB/s.
My question is do all 4 ports on the back share that bandwidth, are they like a mounted hub?

What about if you add a USB PCI card, will those ports also share bandwidth with the other native ports?

Hope the question is good enough. Thanks for any feedback.

 

[pmr]

The usb ports are independent till you reach the limit accepted by the southbridge.

If a mobo says it supports 6/8/10/12 ports, then that number of usb devices will run at full speed.

If you use a pci card, it will run trough pci lanes and nothing has to do with the usb ones.

The only way to share bandwidth is with a hub plugged at one usb port

 

[sneskid]

thanks dude

 

[Joe_The_Dragon]

The usb ports are independent till you reach the limit accepted by the southbridge.

If a mobo says it supports 6/8/10/12 ports, then that number of usb devices will run at full speed.

If you use a pci card, it will run trough pci lanes and nothing has to do with the usb ones.

The only way to share bandwidth is with a hub plugged at one usb port

A mobm may have 6-12 ports but only have less usb controllers also there is chipset bandwidth limits + cpu over head.
A pci card may have less cpu over head.