I have had a look at the SMP and NUMA architectures which are for multiprocessor systems.
I found a number of interesting resources:
SMP means symmetric multiprocessor while NUMA stands for Non-Uniform Memory Access. Actually SMP is a type of UMA, i.e Uniform Memory Access. Basically, SMP processor share all the same memory, this imposes some overhead on the cache of the processor to speed up the processing. NUMA architectures (of which different flavor exist, in particular cache-coherent models, aka ccNUMA) have a non uniform access to memory, some processor have access to local caches. In that way, the processes do not need to synchronize to access the data.
