"Most of the time, it's I/O waits anyway" I believed this for years too. But after some years in production I do no longer believe this. If you cache a lot HTM

"Most of the time, it's I/O waits anyway" I believed this for years too. But after some years in production I do no longer believe this. If you cache a lot HTML or data, then I/O is no longer an issue and the load of your app servers is CPU bound (mostly rendering, I was suprised about this). Faster language => less app servers => less money spent.