every processor will last long more than 10 year's but when it is come to overclocking it's limited upto 4 or 5 year's.
Well... not exactly true.
My IBM ThinkPad T40 with it's single core Pentium M 1.5GHz was a great CPU back in the day can continued to be so until probably around 2007 / 2008. By that that time software started to become a bit too bloated to run well on that CPU. Even the internet started to become a bit too bloated. Browsing the web was a breeze initially, but with things like java code running in the background and Adobe Flash running rampant on just about all webpages (an browsers have also become bloated) surfing the internet with that old laptop gets pretty laggy at times