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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...

8 comments
Pazman
Pazman

I'd like to see a comparison betwen competing back-ends for thin client computing: - Virtual desktops using VMWare on high-end servers - Terminal services/Citrix on top of Windows servers - Dedicated low-cost blade PCs (HP's consolidated client infrastructure is one example) It's not so much that thin client computing can save you money, but which back-end to use with it.

jon_saxon
jon_saxon

This is a fine starting point for additional analysis. But, as others pointed out, TS CALs are not free. However, $700 every three years is not the TCO of the PCs in question here. There are significant costs of ownership associated with each of those PCs each and every year. And I expect it would be much higher than the cost of ownership for the terminals. So you would need to work in the delta of the cost of ownership of the PCs versus the terminals. So you have the TS CAL license costs versus the cost of ownership for those PCs. What else is missing? I wonder about the estimate for a 6 year replacement for a terminal. Sure the things won't break in 6 years but will they be obsolete? Six years is an eternity in IT. If the there is a profound shift in technology in six years, not unlikely, you lose all the projected savings in this instance. For example, you swap out your accounting PCs with terminals but three years down the road you have to upgrade to a new accounting version and it doesn't work on your terminal or, more likely, your terminal server won't serve up this new application? Well, you can't project that but I suppose your project plan has a risk analysis and mitigation section too. In all, the model is a good start but is missing some key costs on both options. Fine tune the example for your needs, making sure you have factored in your unique costs and circumstances, and you have a reasonable plan to present to management.

Scott Lowe
Scott Lowe

You are definitely correct on all points. There are a huge numbe rof variables to consider in all of the scenarios I put forth. I try to make them simple to a point, but with enough information to see the picture. As some pointed out, I did not include TS CALs either. Simply put, TS CALs are priced radically differently depending on the vertical. In higher education as a part of a campus agreement, they might as well be free, but in a corporate environment, not so much. These are very much intended to be starting points for discussion -- nothing more. Also, I do think that the right terminal can serve for six years as long as it's upgradable from a software perspective to support newer protocol versions. That is also assuming, as you point out, that your infrastructure/desktop environment doesn't have to undergo a paradigm shift at some point in the cycle.

stod73
stod73

I'm not an expert on Windows 2003 Terminal Server CALs but it must be noted that there would be a significant cost for licensing to use terminal computing. I also think it's important to point out that you would most certainly need an IT professional on staff that understands TS and have the ability to administer. There will also need to be a fair amount of training for the user community to understand this new environment. Between CALS, training and upgraded staff you will have most likely ate up any savings achieved buy going thin. But don't get me wrong. If you can go thin I highly suggest it. Software deployment is superior. User downtime is almost non-existent. All and all a better system for any infrastructure team.

Forum Surfer
Forum Surfer

Forgive me but I didn't read (nor did I go back and re-read) your previous post. How did you go about obtaining your power consumption figures? I say this only because I've taken reading before that turned out a bit different (granted all things should turn out different, but not this drastically). I did some calculations on the cost of installing switchable power strips to save cost after hours. I used a very accurate fluke meter with a wrap-around lead to measure my actually amps. After several calculations the wattage saved was severely offset by the purchase of switchable strips or outlets. But even still, the difference was very small in the actual power bill (barely enough to notice) for standby vs off completely. I'm not disputing you by any means, I just wanted to see how you arrived at your figures since I had performed similar studies. Just a thought...I liked your article, however. For me I have too many apps that aren't TS friendly to even contemplate going that route. Nevermind the fact that I am not a big fan of it!

glennj
glennj

I've been running terminals in a school district since 2004. I bought 500 TS CALs for $325 - can't remember if education got a discount for this or not. I did no training for this environment, as it wasn't necessary. Students just said, wow, these computers are really small! End users could tell no difference - all they had to do is click an icon on the desktop that started the RDP session.

Scott Lowe
Scott Lowe

Regarding TS CALs - very good point. I should have included that in my analysis. Of course, if the organization wants to avoid TS licensing, they could do VDI using Virtual Server 2005 and just use Remote Desktop from a terminal to access individual VMs. I also agree with the need for good IT folks to pull this off!!! Scott

wdewey@cityofsalem.net
wdewey@cityofsalem.net

Wouldn't using virtual machines automatically cut down the number of total users a server could support? Also, VM's probably require some type of Desktop licensing that would need to be factored in.

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