On Monday, 1 July 2013 at 17:19:02 UTC, Jonathan Dunlap wrote: > Thanks Manu, I think I understand. Quick questions, so I've > updated my test to allow for loop unrolling > http://dpaste.dzfl.pl/12933bc8 The loop body in testSimd doesn't do anything. This line: auto di = d[i]; copies the vector, it does not reference it.