Top is updating your screen. top, term and X are all consuming CPU cycles -- with unfinished graphical drivers.
When you reduce the top update frequency (type 's', then a number larger than 3 and ENTER), you can see the percentage go down.
Then there is hps_main kernel thread, which I assume to be busy for real (maybe due to logging? I guess this one is generating all those log entries, keeping several more processes busy at that).