Wind

I have a general question about the wind on Mars. There has been much talk about wind erosion and ripples and dunes caused by wind.
Since the air pressure on Mars is only 1/100th of that on Earth, it would seem that it would take an enormous wind to move a grain of sand. Does anyone know what the wind speeds are like? We have seen dust devils, and "red outs" that stir things up pretty good.

Stan