go
    | anArray numProcesses step |
    anArray := Array new: 60000. "Assume an even larger number for realistic examples"
    numProcesses := 32.   
    step := anArray size // numProcesses.
    1 to: anArray size by: step do: [ :i |
        [   
            i to: (i+numProcesses-1) do: [ :j |
                anArray at: j put: j ]
        ] fixTemps fork.
    ].
    ^ anArray.

However, it doesn't work except for small numbers. I'd be happy if somebody would be able to provide a fixed version; I can't work it out.