USB Cable Specification

[pna]

Hi,

I've replaced the 1.1 USB ports on my PC with a USB 2.0 PCI card and have ordered a new USB 2.0 hub.

Does anyone know how I tell the 'spec' of the peripheral cables attached to hub? I can see wording that says 'Type CM' on one, but the others are blank.

Thanks

 

[Igorian]

Unfortunately, there is no easy way to tell. Some cable manufacturers will stamp USB2 or hi-speed on the cable sleeve.

The original USB1.1 specification for cables was actually more than adequate for USB2.0. Unfortunately, some cheap components have made it to market which don't fully comply. I suppose, what I am trying to say is, suck it and see.

 

[AdamW]

Unfortunately USB2 does not include "graceful degradation"...

Graceful degradation is what you experience on an old 56k modem: the line quality is determined during the handshake, and the modem will run as fast as it can on that phone line.

However, a USB2 device will try handshaking for full USB 2 speed (480mbps), and if that fails will switch down to USB1.1 speed (12mbps). No handshake speeds inbetween, even if you only need a speed barely above the USB 1.1 spec.

You might even find your new USB2 hub comes with a suitable cable.

 

[pna]

Thanks guys.