What makes our Systems Slow?

http://stellar.cct.lsu.edu/files/hpx-0.9.11/html/hpx/tutorial/intro/slow.html

• Starvation occurs when there is insufficient concurrent work available to maintain high utilization of all resources.
• Latencies are imposed by the time-distance delay intrinsic to accessing remote resources and services.
• Overhead is work required for the management of parallel actions and resources on the critical execution path which is not necessary in a sequential variant.
• Waiting for contention resolution is the delay due to the lack of availability of oversubscribed shared resources.