Intel Galileo vs Arduino for project (Audio based)

Hi I've decided on making an automatic tuner for my college project. We were handed intel Galileo's at start of term and encouraged to use the arduino ide to program with. We already worked with Arduino Unos so this seemed logical.

But i've noticed massive errors with Galileo compared to Uno. For example i wrote a frequency detection program using the micros() function and interrupts.. The single note from guitar string is converted to a square wave pulse (in hardware) , this is fed to Pin 2 (enabled as an interrupt ) , the average period is found over 3 or more pulse and frequency is printed to serial port for user feedback..

Now the problem... Using the Uno i get very consistent results +/- 1 hertz accuracy (D string 146hz approx).. With the galileo its absolutely abysmal ..readings are all over the place (anywhere between 140 - 300 hz)..

Same code exact code for both.. So can anyone tell why the Galileo reacts like this?

Maybe - http://allynh.com/blog/intel-galileo-getting-to-grips-with-gpio-speeds/ ?

interesting indeed .. well more dissapointing lol.. So for precise timing I should just stick with the Uno?

Yes the way the Galileo input output is designed is crap. It uses the slow I2C bus so is useless for anything real time. I told the design team it was poor at the launch. The version 2 is hardly very much better.