Lots of helpful replies and shared experiences. Thanks.
mettelus
I just reformatted this machine with a particular focus on latency. I need to put together a more readable list of things, but in short: I did disable core parking right away, turbo mode/speed step/HPET were all "immaterial" to items that jack latency through the roof in the system, OC increases heat and induces page faults (as well as dielectric breakdown of the CPU) so have never used this. Power options to idle/sleep nothing are also important (run through the entire list in the "advanced power settings" pop-up).
The biggest hitters to latency are "automatic [anythings]" with Windows Search (disabled in "services.msc") and network auto discoveries (in Control Panel\All Control Panel Items\Network and Sharing Center->"Change advanced sharing settings") being # 1 and #2. Both of those are very aggressive and self-starting unless specifically disabled. I even brought this back online with Avast 2015 (in "Silent/Gaming Mode"). Highest page faults come from Internet Explorer, not surprising really, but the system can be online (was in the forums at the time), SONAR open (transport was not running during this capture), Avast running, and looks like this:
Depending on Internet Explorer usage the total reported fault count (bottom bar) will ramp up into the red.
OK, made a note to check once more on advanced power options and automatic services ... as regards networking I seem to get away with simply having LAN unplugged (no WIFI installed) ...
mettelus
The other big picture item is to monitor "msconfig.exe," both services and startup tabs for non-essentials (many programs will load themselves into boot just by starting them). Hardware support/virus protection are essentials (not recommended to disable those).
Doktor Avalanche
Process monitor and process explorer are your friends here.
"msconfig" is your friend when it comes to disabling basically anything you can live without, especially as reactivation is just one click + reboot. nothing to destroy there by mistake. I basically have everything non-Microsoft and not hardware related (graphic & HD controller) disabled.
I even disabled anti-virus because the DAW is offline and only goes online for monthly updates (win8, C3, NI, XLN). No files from clients enter my system directly via USB sticks - simple & effective policy.
So my processes tab in task monitor starts almost empty.
Doktor Avalanche
Info and discussion on HPET here, I keep it on.
http://forum.cakewalk.com/tm.aspx?m=3237094
I follow that HPET discussion ... very interesting. Especially as most information on the web is from a gamers perspective and IMHO does not necessarily translate directly to optimum audio performance (as we don't have all that 3D graphics "overhead") ...