There is a concept of creating CPU Partitions in CMPs, e.g. one can create a full partition of 32 processors, Or one can create two partitions of 16 processors each, these two partitions will be visible to the OS installed as two machines. Similarly for 32 processors it is possible to create 32 partitions at max each having a single CPU.
In case of LINUX/UNIX OS the CMP technology is proven to be very best, whereas in case of Windows 2003 Servers installations, there are certain limits for partitions having number of CPUs, like for a windows 2003 installation the maximum CPU in a partition can only be 4, if more CPUs are assigned severe performance degrade are observed. Even on 8 CPU partition the performance is compariable to the performance of a 2 processors partition.