http://en.wikipedia.org/wiki/Time_Stamp_Counter http://en.wikipedia.org/wiki/Time_Stamp_Counter "The issue has two components: rate of tick and whether all cor

http://en.wikipedia.org/wiki/Time_Stamp_Counter http://en.wikipedia.org/wiki/Time_Stamp_Counter "The issue has two components: rate of tick and whether all cores (processors) have identical values in their time-keeping registers. There is no promise that the timestamp counters of multiple CPUs on a single motherboard will be synchronized. In such cases, programmers can only get reliable results by locking their code to a single CPU." The entry also mentions that hibernation can affect the counters. I wonder if power savings implementations that speed up or slow the CPU could also have an effect.