OT: Is the AMD Phenom processor upwards compabible with the Opteron

[Jonathan Ryshpan]

Configuring the kernel I came across a choice between generic-x86_64
processors, and the Opteron/Athlon/Hammer/K8 processors.  My system has
a 4-core Phenom processor.  Questions:

     1. Is the Phenom compatible with the Opteron/etc?  I.e. if I
        configure for the Opteron, will my kernel be reliable?  (This is
        not as easy to find out as I thought.)
     2. How much of a performance advantage is there to configuring for
        the Opteron as against the generic?

Thanks - jon