Every once in awhile, I drop in to see what's happening and I can't help but to respond to these query.
FPS has nothing to do with freezing, stuttering or micro stutters. It's just the most base, coarsest method of trying to measure performance.
If you do some research in the archives looking into tech conversations from myself, Tamper, Parky, BirddogICT, Panama Red, Homeboy, to name a few, you'll find a wealth of information regarding your problems.
Since your having a full freeze to the point that Task Manager is not functioning, you experiencing a full crash caused more than likely by a "buffer overrun".
There aren't any "patches" for this; no "update" will solve this either. I don't mean to sound or be condescending, but you haven't begun to optimize OFF or WOFF for your particular systems.