Removed the Fedora installation with Lazarus 1.4.4 and installed 1.6 on the same OS (Fedora) and with an empty project Lazarus never uses less then 35% cpu power, and the strange thing is that the cpu usage spikes after minimizing/hiding the IDE. If I, by using the tools menu, select "rescan fpc source directory" the cpu usage goes down, but after a couple of minutes it's back up at 50% or more, with the IDE hidden and idling.
No options are changed, it's a fresh install of Fedora, fpc3.0 and Lazarus 1.6, tried on both HP Elitebook8460p (low end) and Toshiba Kira
*edit* screenshot from HP EliteBook, running fresh install of Fedora, FPC3.0, Lazarus 1.6 64bit, and Google Chrome installed. Can add that I've tried both 32 and 64 bit with same result