I would really like to be able to set things like browsers to not use core 0 so that single-threaded games don't have their performance messed up.
The Windows process scheduler doesn't work the way you think it does; pegging things away from ACPI CPU 0 wouldn't "solve" anything.
The thread scheduler will rotate threads through all available cores, even if that thread is "single threaded." You're better off pinning the single threaded job to a single CPU than trying to evacuate the first enumerated ACPI CPU. You can see this for yourself by running a single threaded, highly intensive application on a multicore CPU with a bunch of other tasks (that are "less busy") running simultaneously. You'll see your 100% CPU peg float around between logical cores within task manager, if you have it set to show ALL cores versus the CPU average.
Part of this pathological behavior sometimes works against the best interests of your power management, specifically talking about core parking on "inactive" cores. As Windows stupidly revolves threads around your processor package, it will force a wake-up state on parked cores, which can result in stuttering on low-threaded CPU-intensive tasks.
If you search my post history for "core parking" on this forum, you'll find a larger thread that goes through quite a bit of this in larger detail.
Much later edit: The thread in question is here -
https://forum.beyond3d.com/threads/...neys-on-our-pc-cpus.53809/page-3#post-1711294
it wasn't as detailed as I remembered
hehe...
Oh, and unrelated to the core parking issue...
I've had the Windows 10 preview build inside a Hyper-V guest for a few months now, just to tinker with it. I finally decided that I wanted to play with it on a physical box, so I dug through the random junk pile and dragged out my wife's old 2009 Dell Mini 10v -- an Atom N270 powered, 945GMSE chipset netbook with 2GB of ram and a 500GB Western Digital hybrid drive plugged into the onboard SATA1 port. Let's be blunt: this is a very slow box, even with the hybrid drive.
Equally blunt: Windows 10 performance on this box is nothing short of astonishing. It goes from power button to desktop in about 12 seconds, and is remarkably usable after it takes about 20 more seconds to "settle down". As you might expect, it's massively CPU bottlenecked, but outside of the boot process, you really can't tell.
It's markedly faster than Windows 7 Pro on this craptastic hardware. Color me impressed.