(When I finished my computer Sci degree, I decided not do as PhD as I believed that in order to get a programmer position, most employers valued 3 years more experience as a programmer greater then a PhD.)
Reading this site, it seems normal for a PhD to take 5 years, however in the UK most people expect a PhD to take not much more 3 years unless the student is being lazy.
If I saw the CV of someone applying for a computer programmer job unrelated to their PhD and they spend 5 years on a PhD, I would questions if they were worth interviewing just on that bases.