USB port/USB hub question.

[Denvers Dawgs]

Recently I've seen USB hubs that have 16+ usb ports on it and it just plugs into the pc with 1 usb cable. Is it actaully possible to have 16 devices running simultaneously, without lag or slow down? I've always been curious about this...

[guns1inger]

Theoretically you can have up 127 USB devices piggy-backing off each other and running simultaneously. I'm not sure why you would want to, but if you are the type of person who must have a USB fan, lamp, Xmas tree, fishtank etc. then it's nice to know you can run them off one hub.

[redwudz]

And you might want to get a powered hub for that if you want to run USB powered peripherals. A computer can only put out a limited amount of power over the USB ports.

[IKnowNothing]

Recently I've seen USB hubs that have 16+ usb ports on it and it just plugs into the pc with 1 usb cable. Is it actaully possible to have 16 devices running simultaneously, without lag or slow down? I've always been curious about this...

Although you can have upto 16 devices you still only have the same "limited" amount of bandwidth to push your data through (plus time for switching).

Depending on your pc there may be an internal hub and only 1 USB stream and so upto 127 USB devices on the machine as a whole rather than per port!

Also the power supplied by the pc is VERY limited (milliamps) so ALWAYS use a powered hub to prevent damage to your pc

[edDV]

Also, unless the hub is rated for USB2, it will cause all connected equipment to drop down to USB 1.1 (12 Mb/s shared).

I wouldn't use a hub for a hard drive.

Refs
http://en.wikipedia.org/wiki/Universal_Serial_Bus
http://www.everythingusb.com/usb2/faq.htm

[Denvers Dawgs]

Thanks guys, I don't ever plan on using a usb hub, the 6 usb ports on my pc are plenty for me.

[ViRaL1]

http://www.engadget.com/2007/01/30/centurys-16-port-usb-2-0-hub-for-two-pcs/

This is one is 2.0 and should be able to handle a quite a bit, but in the end you're still splitting one root hub into 16 ports, even less if you have something else plugged into the other port on the same root hub.