- 4x4 — 2 seconds
- 5x5 — 3 seconds
- 6x6 — 7 seconds
- 7x7 — 12 seconds
- 8x8 — 20 seconds
- 9x9 — 38 seconds
My 5x5 is pretty optimized, and the rest are decent. My 9x9 has some room for improvement though.
If you haven't played before and you'd like to play, you can do so here: https://0hn0.com
Just know that my first 9x9 took maybe 30+ minutes. It takes many, many boards to get competitive!