I notice my clock tends to go up to 1.7GHz as well sometimes when I touch the screen (monitoring with System Monitor Lite). Other times it might jump from 200MHz to 400MHz, or some other random value up to 700MHz. Never saw it go to 1.0GHz.
Maybe 700MHz is the default toughboost pulse. I am used to the KTManta kernel and it uses 1GHz as the default.