Hello chikhim;

Yes, you can slot different CPUs in the rack for multicomputing, as long as they support it . See the list in the following FAQ, and check out the multicomputing sections in the suggested manuals (specially the second one, "CPU specifications", section 3.1: Multicomputing):

What is multicomputing mode and what are the differences to operating in the segmented subrack?

Hope this helps,

Daniel Chartier