I'm still doing my first overclock. I installed a new CPU cooler on Thursday night & have slowly been stress testing/raising FSB/adjusting memory straps & dividers/adjusting MCH, CPU and DDR voltage ever since with lots of prime95 + unigine heaven stress testing overnight & during the day.
So that's like 4+ days for me! But I am cautious.
I have got to a 35% overclock on the CPU/FSB and just over 10% overclock on the RAM (though it is rated for more).
So far I have had one blue screen and two failures of prime95 through testing 15 different groups of BIOS settings.
35% that sounds very good