I have no idea, and searching didn't come up with anything. It actually doesn't make sense to me, especially being an odd number. Everything that I've read about vectorization says that the variables should be aligned and some multiple of 8 or 16 bytes. 1030 would be a better choice if we were to include the ghost zones. I was taking the word of someone from the "vector age" ;)

What about the +7 offset? Does a value of 1031 cause stack overflows?

I misinterpreted the response on the list as it not being necessary. I'll put it up to 1031.

Does anyone know where the +7 comes from anyway? (Ghost zones of 3 gives six.) I say keep it and assume this is for an actual max size of 1017.

I have no idea, and searching didn't come up with anything. It actually doesn't make sense to me, especially being an odd number. Everything that I've read about vectorization says that the variables should be aligned and some multiple of 8 or 16 bytes. 1030 would be a better choice if we were to include the ghost zones. I was taking the word of someone from the "vector age" ;)

Okay. Then in the absence of a clear cut reason, let's just cut it off at this point and say 1031 it is! :) I'm +1 on this.