The last time I worked like that was when I was working on bootstrapping a start up while having a day job. I did close to a 20 hour schedule for around 4 years. This was only a year back, when I decided to take a break for an year or so.
Hardwork doesn't always give you results, But not working hard almost certainly doesn't. Well unless you have rich parents, or in-laws, or spouse or you inherit money someway- Or you are plain lucky to have god fathers in the industry bailing you out time to time, taking care of your career and financial growth.
For every body else its the plain old brutal torture.
There are some human anomalies that can thrive on that little amount of sleep but I would think for most people this would lead to poor productivity at best and be extremely detrimental to health at worst.