Cloud Computing – The New Timesharing?

I was having lunch with a colleague the other day and our conversation turned to cloud computing.  He had recently made a presentation to some CIOs and put forth the thought that cloud computing was the new version of the old timesharing concept.  An interesting idea; maybe things haven’t changed so much.

Let’s look at a couple of extracts regarding the history of computers and see if there is a resemblance to cloud computing today.

In the 1970’s, you dealt with what today are called mainframe computers.  There were 2 ways to interact with a mainframe. The first was called time sharing because the computer gave each user a tiny sliver of time in a round-robin fashion. Perhaps 100 users would be simultaneously logged on; each typing on a teletype machine.¹ Virtual machines today could be considered the tiny slivers of time back in the 1970s.  Providing additional capacity to the 100 companies using the Infrastructure as a Service (IAAS) capability on demand from their “teletype” is sharing compute power, maybe not in round robin fashion, since things have speeded up considerably since then, but still time sharing of resources.

A timesharing computer was “one organized so that it could be used simultaneously by many users, each person having the illusion of being the sole user of the system – which, in effect, became his or her personal machine.”² This is interesting since anyone using applications not resident on their personal device qualify here, in the cloud or not.

It was also more efficient, many thought in the late 1960s, for a company (the timesharing utility) to own the mainframe and rent computing power than for each business to own an independent computer.³ Add a few services on top and it seems to me you have Platform as a Service (PaaS).

The types of resources that can be shared have grown and the metrics for charging may have changed, but the fundamental concepts seem pretty similar to me.

Like centralized and decentralized, what goes around comes around.

Here’s another perspective: Cloud Computing: A new name for an old method

© Ellen Terwilliger 2012

¹ http://www.computersciencelab.com/ComputerHistory/HistoryPt4.htm

² Campbell-Kelly and Aspray, Computer, p. 186.

³ Campbell-Kelly, Martin and Garcia-Swartz, Daniel D., Economic Perspectives on the History of the Computer Timesharing Industry, January 20, 2006, http://papers.ssrn.com/sol3/papers.cfm?abstract_id=880740