I've just started using SadMan Sudoku, and noticed that the CPU usage is sometimes very high. Why is this?

A. Sudoku is busy building up a library of puzzles. It does this in the background so that there's always a puzzle ready when you want one. Once the library is full, which may take several hours, it will stop. You can:

  1. Leave it running unattended for a while to give it a chance to fill its library without the fan bothering you.
  2. Disable background creation of puzzles. View -> Options -> Options tab -> Create puzzles in the background. But if the library is empty when you want a new puzzle, you'll have to wait while one is generated.
  3. View some stats on the library to give you an idea how much longer it will be annoying you. View -> Library statistics. The library is set to hold 1000 puzzles, roughly split across the various grades, with a bit of leeway, works out at 138 puzzles per grade, but with fewer diabolical.