Four years was the average, now it has moved to about five to six years.
Weve got to go fix some of those things.
There are several reasons why the PC market has slowed down.
Also, PC upgrades have slowed because current operating systems can run well on older Intel-based PCs.
Intel should manufacturer processors in a way that they can deliver better real-world performance when pitted against their predecessors.
source: www.techworm.net