I'm trying to understand how Linux handles two different configurations

Intel dual cpus with 6 2.9 ghz cores, 2 hw threads per core. Total 24 threads

Amd dual opterons with 12 1.9 ghz cores, 1 thread per core. Total 24 threads.

In /proc either configuration looks like 24 cpus. Does Linux schedule them differently?

Does a single threaded process that is cpu bound run proportionately faster on Intel because of the clock rate? (assuming there are idle cores).

I'm particularly interested in this for a thin client server, running 20 active desktops with a mix of browsers, email clients, open office, latex, etc.