Now that I’ve got the Eternity II solver running on the cluster in a sustained way and I don’t intend to make any major changes to it, it’s a good time to see how it’s doing! Though it was exciting to get the clue pieces, unfortunately it meant I had to restart the run, which got setup in November, which means I’ve run for just over a month. That said, the progress is pretty good!
We’re at nearly 20 million boards generated, with about 5 million of those boards tested against. Done boards are boards that produced new results to look at, while Invalid boards are boards that were shown to result in 0 possible configurations after examining it. It’d be nice if that Invalid count was a little higher as each invalid board prunes off large swaths of the search space, but can’t expect too much. This is a hard problem after all.
I’m also happy with how deep we’ve managed to get. The board selection is random, but definitely favors deeper boards (boards with more pieces placed) than shallow boards. On December 26th it found a board with a depth of 150, but it was rather quickly marked as Invalid since no other pieces could be found. Over half of the boards have 23 pieces placed or less, so there’s still a lot of work to be done!
