"The cornerstone of the p690 is IBM's Power4
microprocessor. The "server on a chip" contains two one-GHz-plus
processors, a high-bandwidth system switch, a large memory cache,
and I/O capabilities. The server was designed this way to conserve
energy and dramatically outperform other servers that have more
than twice as many processors. The Power4 processor pumps data
between the memory cache and the processor at nearly 125 gigabytes
per second, or the equivalent of moving 25 full-length DVD movies
in a single second.
The p690's palm-sized, eight-processor, multichip module has the
equivalent processing power found in the larger system boards of
other high-end servers. These ultra-dense building blocks are
designed to contribute to the server's lower cost of ownership by
providing more computing power in less floor space while consuming
less power than other systems.
The p690 can operate as a single large server or be partitioned
into as many as 16 "virtual" servers, running any combination of
the AIX 5L and Linux. These virtual servers differ from the more
common "hard" partitions that require at least four chips. The p690
is also designed to dynamically reconfigure partitions to meet
changing workload demands without being taken offline."