Windows PCs vs. X Terminals: A Cost Comparison
The Mark O. Hatfield Library at Willamette University has used networked X terminals in its public and staff computing environments since 1995. The original workstations were NCD and Tektronix thin clients, but over the last two years, we have been replacing the systems with recycled PC hardware that otherwise would have been scheduled for replacement.
An X terminal is distinguished from a standalone personal computer in that X terminals rely on a networked computing model in which applications such as the desktop environment (window manager), Web browser and office software are hosted and run on a centralized application host located elsewhere on the network. The application host usually runs on heavy-duty server hardware, leaving the terminal workstation with the more trivial tasks of responding to input from peripherals such as the keyboard and mouse and drawing graphics to a monitor.
The Hatfield library currently has 25 of these X terminal systems deployed as specialized staff computers and kiosk-style public computing stations. They connect to two X client application hosts powered by x86-based PC server hardware running Red Hat Enterprise Linux, XFree86, XDM, the GNOME 2.4 desktop and the Mozilla Web browser.
In public computing environments, the model of centralized network computing has several advantages over traditional standalone workstations in that it:
Provides a no-cost alternative to expensive desktop deployment and cloning packages, such as Symantec Ghost, because new software is added to a single machine rather than deployed and run on each individual workstation.
Provides a centralized environment that is superior to standalone computing for backing up and maintaining user data as well as company proprietary data.
Enables institutions to maintain a homogeneous, flexible software environment even on PC hardware that has been purchased over a period of several years.
Extends the lifespan of personal computer hardware, yielding an overall decrease in investment in new hardware.
Is not susceptible to Windows-based viruses and spyware. Required security patches need be applied only to one system in order to update multiple systems.
As a rule of thumb, personal computing hardware at this institution is recycled out of the system after five to six years. Hardware and software manufacturers recommend a three-year purchasing cycle. The cost of replacing the 25 workstations deployed in our various labs and on staff workstations with new personal computers would be roughly $25,000.
Instead, we are replacing Windows with Linux on PCs that are six years old or even older and keeping those systems in service. In Addison to reducing the cost of new hardware and software purchases, it extends the return on investment of hardware already purchased.
Because these systems are being recycled out of service, there is no additional input cost for personal computing hardware. These literally are systems that otherwise would be thrown out.
Instead of purchasing new PCs, we instead make purchases on server hardware on a four-year cycle. Historically, one dual-processor x86 system can power applications for up to 25 X terminals.
By adopting this model, we have extended the lifecycle of our antiquated desktop hardware from seven to ten0 years, and we still are able to run current applications, including modern desktop environments, proprietary Java applications, Web browsers and office software.
Desktop PC model: 25 new PCs every three to six years.
Linux X Terminal Model: Two new application hosts (server hardware) purchased every four years with a two-year stagger. Adding recycled PCs as they become available.
Windows Licenses: Windows $2,500 (est.); Symantec Ghost $1,700 (+ $525/annum); Symantec Antivirus $1,544.25 (+ $525/annum)
Linux: per server annual subscription is $50 beginning in 2003.
Table 2. Software Purchasing Cycle Cost Comparison Over 15 Years
Based on our experiences over the last eight years hosting both PC and X terminal labs, we estimate that we would hire and retain roughly the same amount of administrative and technical staff to service this number of systems regardless of whether they are Windows or Linux-based.
During 2003 and 2004 so far, however, we have seen a dramatic rise in the amount of time spent patching Windows systems and removing ad-ware, spyware and viruses from unpatched systems and re-imaging OS images. This rise is time spent on these tasks may increase dramatically our administrative costs going forward.
As far as installation and maintenance, for Windows PCs, the weekly manual processes involve cleaning old data off of primary ghosting systems, building three updated workstation ghost images with Windows updates, A/V updates and ad-aware updates. Then there is an automated push of ghost images to the workstations. The total time spent on this is three hours two times a week.
For Linux X terminals, no regular ghosting or updating of images is required. Primary work involves fixing bad hardware when installing antiquated systems and setting up each system as an X workstation. This all takes two hours per newly installed workstation. A new client application host installation requires 16-20 hours to set up and to complete the migration of applications.
Excluding administrative costs, the 15-year cost of 25 Linux systems in a lab environment is estimated to be $41,359 versus a 15-year cost of $100,000 to $155,000 for Windows PCs serving the same function. Although these estimates are based on rough cost estimates, the overall cost of hardware and software deployment, coupled with the shorter overall time spent on administrative tasks, yields significant cost savings over long-term deployment cycles in our work environment.
Salvador Peralta is the systems administrator for the Mark O. Hatfield Library at Willamette University in Salem, Oregon.