I tried mining some with some shifts on the range around 380 but miners gave me 'illegal instruction core dump' error.
I then noticed that it gives me that error for every shift bigger than 192. So i put my miners running with shift 187-192. Lets see what happens.
It seems to work. Any reason why i get this error? Can my binaries be the problem?
My PPS is halved btw.
Looks like you've found a world record already on a shift 192--length 7546
https://bchain.info/GAP/block/8af4723fc2e9b9f460455ab09d38dcc9649d9a06e2927783a0e89c6efd522075