http://research.google.com/pubs/archive/36448.pdf http://research.google.com/pubs/archive/36448.pdf "So why doesn’t everyone want wimpy-core systems? Because i

http://research.google.com/pubs/archive/36448.pdf http://research.google.com/pubs/archive/36448.pdf "So why doesn’t everyone want wimpy-core systems? Because in many corners of the real world, they’re prohibited by law—Amdahl’s law. Even though many Internet services benefit from seemingly unbounded request- and data-level parallelism, such systems aren’t above the law. As the number of parallel threads increases, reducing serialization and communication overheads can become increasingly difficult. In a limit case, the amount of inherently serial work performed on behalf of a user request by slow single-threaded cores will dominate overall execution time."