Six months ago I retired a web server I had been using for 11 years. I commemorated the occasion because I was paying for a server to host my sites that had become a museum piece.
Linux is so good at running Apache, MySQL and PHP that your hardware can become a decade out of date without performance becoming an issue.
My other two web servers were almost as old. The company I use for hosting, SoftLayer, recently offered me a deal to upgrade. A sales rep told me, "After reviewing your account we noticed that you are still are on our older legacy platform. Many of our customers have migrated off this platform, and you are one of the few who still remain on it."
I just completed that move. My sites are running on new servers over 20 times as fast and my monthly hosting costs have dropped from $652 to $326. That will save me almost $4,000 a year.
If you see this post, it worked! One bug down, many more likely to go.