It is unbelievable to me that after 5+ months we have Intel pointing its finger at Microsoft without giving a link or case number, and Microsoft saying dunno what you're talking about, replace your hardware. There are 120+ posts about this bug at Windows 8.1 x64 - Low memory while playing full screen games - Microsoft Community, plus several other threads out there. That makes hundreds of users reporting it, plus presumably many times more who either are lurking or haven't tracked down the threads. My own laptop has been crashing every couple of days since it auto-upgraded to Win8.1, unless I carefully avoid ever maximizing a window, and I don't even play games.
Quite possibly Windows has a bug it should fix, and Intel could work around it like other driver manufacturers but hasn't bothered. Blaming a lower-level bug instead of providing a workaround is a classic thing companies do when they're run by techies who don't understand customer service.
This is the worst-handled bug I've seen in my 20+ years in tech.
PS I'd like to add my thanks to users like ewtaylo who've sunk a lot of time into tracking down the root cause, explaining it to the rest of us, and following up with MS/Intel. You guys are the one uplifting twist to this woeful tale!