Posted by notzed on Nov 19, 2011; 3:40am
URL: https://forum.jogamp.org/Code-working-under-Snow-Leopard-but-not-on-Lion-tp3296875p3520346.html

Giovanni Idili wrote

 (even though I do not fully understand how the kernel could influence the work group size of the device).

It's actually pretty simple: there are fixed limits per processor.  Register counts, local memory, and so on.

The more of these resources that are used by a given thread, the fewer threads can be executed concurrently.  This might affect the work-group size limit (or not, depending on the vendors design).