I was wondering how much overhead running the NSSP ports as SPI creates on a verdex XL6P running on a console-vx expansion board. I have seen the code at http://docwiki.gumstix.org/index.php/Sample_code/C/SPI I was just wondering how much cpu it takes to run the code and actually utilize the ports. I am designing an autopilot for autonomous quadrotors and I want to build it around the gumstix console-vx. Any help would be appreciated.