generally auto overclocking mechanisms will give you an overclock with very high voltages and lower speeds than you could get. i would be very surprised if this one was any different.
however, as long as the voltages are below the levels deemed safe by intel (can be monitored with CPUz while running prime95) then theres nothing wrong with it
*edit*
hmm, i didnt think the G series of motherboard could overclock. im happy to be proved wrong though