Hmm, looks to me like this is OS driver errors & conflicts & not HW system problems to me.
Anyways, I just looked and notice that Nvidia has updated their Forceware drivers again. Now at
v180.48. I'll have to download & install these & see what happens.

But lately the newer drivers are giving better performance & 3DMark scores & according to this one, its a 10% improvement...I'll check that out.