Data Centers

IT cost containment: Terminal Computing

Before I get started, I'd like to invite you to leave a comment requesting a cost analysis for something you might be considering.  For anything that I can reasonably develop, I'll do so in this space.

In my previous two postings in this series, I've talked about a couple of ways that you might go about containing or lowering the overall costs for your IT infrastructure.  In this part of the series, I'll discuss another possible cost-savings method - the implementation of terminals into your environment to replace some or all of your desktop computers.  Before I begin, let me be clear that this advice isn't for everyone and there are a ton of things that need to be taken into consideration if you decide to go down this route.  For example, do your applications lend themselves to being run in a server-centric environment?  Do your apps "play nice" with one another?  Does your server OS of choice even support the installation of your applications?  Are you apps light enough that the load from 20 or 30 clients can be reasonable supported?  Obviously, I won't be able to cover all of the angles in this posting, but will attempt to provide some semblance of a look at possible financial figures related to a terminal server rollout.

For this posting, I'm making the following assumptions:

  • A typical PC is on a 3 year replacement cycle. I'll use a figure of $700 for each PC. As far as power consumption goes, let's assume that each PC is on for 8-10 hours per day and consumes around 100 watts of electricity (http://checker-board.blogspot.com/2006/12/computer-power-consumption.html). Our sample organization is has 99 PCs on this replacement cycle and each PC is used about 220 days per year. I'm not going to consider monitors in my calculations since you need them regardless of whether you're using terminals or PCs, so they result in no cost difference.
  • A replacement terminal is on a 6 year cycle. Since terminals often contain no moving parts, this is feasible. I'll use a figure of $350 for each terminal. For power, again, these units will be used for 8 to 10 hours per day and consume around 10 watts of power (http://www.computerlab.com/techspecmt15g.htm). Terminals are used about 220 days per year.
  • Terminal servers are also on a 3 year replacement cycle. Reasonably configured, I'll use a figure of $7,000 for each server. For this example, let's use a Dell PowerEdge 2950 rev III server like I did in my previous posting. Since I don't know what Dell might release three years from now, all I have to use for calculation is what exists today. I'm assuming that each server has two mirrored drives for booting the OS and 8GB of RAM. Each PowerEdge 2950 server consumes 323.3 watts or power, which I'll round to 325 watts for the purposes of my calculations. Five servers will handle the workload. Assumption: 25 terminals per server with a fifth thrown in as a spare. The servers run 24x7x365.
  • As per the information located at http://www.eia.doe.gov/cneaf/electricity/epm/table5_6_a.html, I'll use the November 2007 figure of 9.6 cents per kilowatt hour average for commercial power in the United States. I won't be accounting for inflation in electrical costs in this scenario.

And now, on to the calculations, which I'll break down by year over six years.

Desktop scenario Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Total
99 PCs/3 yr 69,300 0 0 69,300 0 0 138,600
Power (9 hrs/day) 1,882 1,882 1,882 1,882 1,882 1,882 11,292
Total 71,182 1,882 1,882 71,182 1,882 1,882 149,892
Terminal scenario Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Total
Terminals (99/6 yr)

34,650

0

0

0

0

0

34,650

Servers

35,000

0

0

35,000

0

0

70,000

Term'l power (9 hr)

188

188

188

188

188

188

1,129

Server pwr (24 hr)

1,367

1,367

1,367

1,367

1,367

1,367

8,199

Total

71,205

1,555

1,555

36,555

1,555

1,555

113,978

Terminal savings Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Total
Savings (23) 327 327 34,627 327 327 35,914

Under the scenario outlined, there is a rather substantial savings to be had by moving to a terminal computing environment.  Not much is saved in power due to the need to operate servers 24/7, but eliminating the year 3 PC replacement saves a lot.

Again, this is a very generic, very rough scenario in which I've had to make a huge number of assumptions.  It does, however, provide a possible outline for you to work with when you consider your desktop computing environment.

About

Since 1994, Scott Lowe has been providing technology solutions to a variety of organizations. After spending 10 years in multiple CIO roles, Scott is now an independent consultant, blogger, author, owner of The 1610 Group, and a Senior IT Executive w...

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