I'm sorry but I can't find a consistent way of reproducing the bug. I presumed
that with 4.9 the bug will still be there but right now, no matter how hard I
try I cannot reproduce with 4.9.4, 4.9.9 and 4.9rc1, I think that in my case is
a hardware problem and possibly unrelated to Reimar bug. It seems to me that
the artifacting varies under load, or under temperature, just that maybe some
kernel versions mitigate the problem and it goes unnoticed and some a aggravate
the problem (IMHO). 
I really don't know what the cause is in my case.