+my $cpu3 = $threesecs->[1]; # user
+my $sys3 = $threesecs->[2]; # sys
+cmp_ok($cpu3+$sys3, '>=', 3.0, "3s cpu3 is at least 3s");
+my $in_threesecs_adj = $in_threesecs;
+$in_threesecs_adj *= (3/$cpu3); # adjust because may not have run for exactly 3s
+print "# in_threesecs_adj=$in_threesecs_adj adjusted iterations\n";
+
+my $estimate = int (100 * $in_threesecs_adj / 3) / 100;