Today's large multi-core Internet servers support thousands of concurrent connections or flows. The computation ability of future server platforms will depend on increasing numbers of cores. The key to ensure that performance scales with cores is to ensure that systems software and hardware are designed to fully exploit the parallelism that is inherent in independent network flows. This paper identifies the major bottlenecks to scalability for a reference server workload on a commercial server platform. However, performance scaling on commercial web servers has proven elusive. We determined that on web server running a modified SPECweb2005 Support workload, throughput scales only 4.8