That's not entirely true...
If you operate it close to it's theoretical Maximum, internal thermal stress (unpredictable and uncontrollable speedpathes and Hotspots) and eventually electron Migration will do their job, regardless of cooling efforts.
Those small Capacitors used on about all Hardware also tend to exhibit a reduced lifetime (if one of those 50Cent pieces blows or bends its Cap, the Hardware is at least disfunctional for a while, or worst case toast
)
It's just a consideration. If you could by another Radeon tomorrow right out of your Pocket (
sufficient money to waste is the Overclocker's best insurance), not a factor anyway.
But otherwise, I'd recommend to refrain from Overclocking, until the Card really needs it to be useful (which shouldn't happen within the next 2 years if you set it up correctly
)
...the road of Overclocking is plastered with destroyed CPU's, Motherboards, RAM's, PSU's and GFX Cards. But usually, people don't speak alot about their failures, thus creating an athmosphere of 'apparent but false safety'...
...after all, success and OC Records sell better than failures