I have a Dell XPS 8500 with I7-3770 CPU and 8 logical processors, 24Gb RAM.
It's running Windows 8.1 (Update 1). Recently I've noticed the System process is using 12.5% (1/8) of CPU on a constant basis.
Using Process Explorer - Sysinternals, I've identified a single thread in the system kernel that is consuming this amount of CPU. This thread has starting address: ntoskrnl.exe!RtlSidHashLookup+0x1ffc.
What is this thread, and what can I do to stop it from constantly using 1/8 of my CPU?