SysInternals' Process Monitor is a great tool if you weren't already aware of it. Get it up and running and set up rules to only output ReadFile operations and hit 'auto-scroll' and you can just watch what the OS and all programs are trying to read.
It's quite incredible how much reading is being done behind my back. In writing the text for this journal entry I've had around 14,000 ReadFile operations speed past.
I saw some suspicious activity from 100's of 1000's of svchost.exe's earlier. Running tasklist /svc /FI "IMAGENAME eq svchost.exe" from the command prompt revealed the offending service to be Windows Defender. At least its not a virus (as such)...
Right at this moment I have Windows Media Player minimized and just playing through a play-list with only 25 tracks in it. Yet I can watch wmplayer.exe scanning every single one of the tracks in my music library. Why?!?! I'm not even using the program and it's not as if they're new tracks to index... so why is it so interested?! Not to mention it seems overly insisted on re-reading SysWOW64\mf.dll - surely once you've read it a hundred times in a row you'll be pretty confident of whats in it, right?
MSIE keeps going nuts with reading all of its temporary files. No idea how many of those are cache-hits for pages I'm loading, but a simple tab-switch generates several hundred ReadFile operations which would explain some of the performance hit.
* shrugs *
What can I do... do I really have to start disabling the functionality of my OS just so I can have a smooth and responsive user experience?
Oh, in other notes, I think my OS is screwed because the 10.1 code I posted before really should work. Go figure why it's not - I suspect I'm missing d3d10_1ref.dll...