<p>What update rate should I run my fixed-rate game logic at?</p>

<p>I've used 60 updates per second in the past, but that's hard because it's not an even number of updates per second (16.666666). My current games uses 100, but that seems like overkill for most things.</p>

Bear in mind that unless your code is measured down to the cycle, not each game loop will take the same number of milliseconds to complete - so 16.6666 being irrational is not an issue really as you will need to time and compensate anyway. Besides it's not 16.6666 updates per second, but the average number of milliseconds your game loop should be targeting.