Gaming PCs can last for a long time, since desktop parts can be easily upgraded. Processors and graphics cards generally last about five years before it becomes necessary to upgrade to keep up with gaming trends. Most gaming PCs will need to be replaced when the motherboard grows too old to work with new parts, as newly released processors and memory sticks occasionally change design and configuration compatibility for new features.  Personally, I've built three different gaming PCs for myself since 2011, going about five years between major upgrades. However, many of the old parts I upgraded from still worked, so I was able to sell them and give them to friends for their own builds.