I re-run this program many times (press "Run" button) and try to choose "representative" minimal time value T. You can set max by hand in the script (e.g. script with max = 16).
max T, ms |
16 0.8 |
512 1 |
1024 1.5 |
4096 8.6 |
With OpenGL backend I get the same ~ 0.9 ms for max = 16 and 4096.
Tested on Intel i3 8100.