Compare the two ends of this window

commit ref when n center lo hi min max
3bd158fb master 2 days ago 10 1.394n 1.244n 1.786n 1.223n 2.016n
89fa694c master 1 day ago 10 1.337n 1.240n 1.484n 1.239n 1.521n
b36a9272 master 1 day ago 10 1.372n 1.267n 1.959n 1.249n 2.055n

Values in sec/op.