I think all 8600 chips have faulty packaging, it's the question of heat-cold cycles load. Mine was dead in 1 1/2 year, others' in 1/2 year, someone's maybe in 3 year or never, but it's a timebomb. Also interesting that Apple has just released an SMC update only for MBPs with 8600 that reprograms the fan control to 'improve high load performance'. Maybe they try to keep the GPU top temperatures lower to push the moment of death further.