Article: New OS Approach Required
Even Microsoft agrees, a high-core count processor requires a different operating system. People that are building embedded systems on high core count processors are already familiar with this approach. Examples of high core count processors are the latest from Freescale (P4080), Intel (Nehalem/Westmere), Cavium (Octeon Plus) and others.
Running a single SMP operating system over all these cores is possible, but it can turn the OS into a bottleneck, thereby reducing the speedup delivered by these many cores. Instead, one can use a hypervisor to carve up the hardware and run an operating system in each of the partitions. A popular configuration is to carve up the multicore chip in multiple 2 or 4-core SMP partitions.