Switch fabric and semantics...

Is a switch fabric the same concept as a switch matrix ?

(halfway down the page) ----> Cisco Catalyst 6500 Architecture White Paper

and ---> https://zone.ni.com/cms/images/devzone/tut/a/42cc553b1260.gif

Or what is it, if there a sustantial difference ?

The 720Gb/S crossbar switch that Cisco are talking about is slightly harder to implement than the other picture but as a concept they are the same.

As far as semantics go I would consider a matrix a static 2D grid, where as a fabric could be of a higher number of dimensions (such as fabrics in the real world are) The idea of standard old school fixed matrix switching is long gone, more complex methods of switching are required to obtain efficiency for a given situation. For IO pin conservation on things like LED/LCD displays Charlieplexing was brought into the world to decrease I/O requirements, and that's only on two dimensions. The actual implementation probably requires a heafty knowledge of mathmatic, as well as the network typical load characteristics are.

If there were no substantial differences between the old way and the new way they wouldn't have made it.