Keyboard Frequency

I am working on making a flight simulator, and to control a lot of the functions. I would like to know what the typical cycle frequency of a keyboard is so that I can cycle through all the controls as quickly as possible. (if it helps I will probably end up using an older keyboard.)

The repeat frequency?

If so, it is adjustable. It was back in the 8088 days too.

It is not a function of the keyboard (I dont think) but a function of the OS.