Celeron Mobile 1500@4170MHz = 178% overclock
 

The first results have been submitted to the Swedish Computer Performance Championship and among these we have Andreas 'Himura' Johansson and his Celeron Mobile 1.5GHz. He managed to push his poor 1500MHz processor to 4170MHz using liquid nitrogen. This brings him to a 178% (!!) overclock. The second best in the history of the competition after last year's winner Robert 'crotale' Kihlberg's 203%.

http://www.nordichardware.com/news,5274.html