‘Thin Client’ System Overview
What is Thin Client?
Thin client is a small, silent, no moving parts device, which simply communicates
with a central server. It has no hard drive, minimum processing power and a very
small amount of RAM. Every time a key on the keyboard is pressed or the mouse is
moved, the thin client terminal sends this to the central server which processes
the key or mouse movement and returns an updated image to the terminal’s screen.
All of the applications are stored and run on the server itself, so the thin client
terminals never need upgrading and therefore have a very long life span – typically
5 to 10 years.
Isn’t this very slow?
No, a standard desktop PC spends the vast majority of its time doing nothing. When
a user is using Excel or similar, most of the time the processor (CPU) is idle.
Thin client uses this concept to share out the CPU of a central machine between
many users – typically 25 to 100 users per server depending on what the users are
doing. Well configured thin client systems run faster than standard desktop PCs
because they have multiple processors, generally 4GB of RAM and very fast RAID or
No. The thin client terminals are very low power devices, they have no expensive
hard drive, minimum amounts of RAM and very low powered CPUs. They are less expensive
than a standard PC, consume considerably less power – and therefore produce much
less heat, take no desk space (they can be mounted on the back of the monitor) and
last longer. They also never need to be upgraded as they are only an interface between
the user and the server.
I have some old PCs – can I reuse these?
Yes, one of the major benefits of a thin client system is that it can take advantage
of old PCs and turn them into terminals rather than land fill. Anything above a
standard Pentium PC can be used in this way.
Are there any other benefits or savings?
Yes, because all of the applications are centralised on the server, all upgrades
and updates are made once to the central server. This results in considerably less
management time in rolling out application updates, anti virus updates and new applications.
Typically a thin client system, with many hundreds of clients, can be managed by
a single administrator freeing up other IT staff to do more productive tasks.
Does this enable me to work from home?
Yes, thin client technology allows you to remotely attach to exactly the same ‘desktop’,
applications, email etc that you would from the office. It looks exactly the same
and gives you exactly the same functionality. You can even print to the printer
in your home if required. This is all accomplished over a secure Internet or dial
Sounds too good to be true – what is the catch?
Thin client can be used for everything including browsing the web, writing letters
in Word, creating spreadsheets in Excel, using Access databases and running PowerPoint
presentations. As thin client terminals are dependent on the CPU of the central
server, they are not suitable for running ‘processor intensive’ programs like Computer
Aided Design (CAD) or very highly graphical applications. With these sorts of applications
the solution is to use a mixture of the two technologies. It is much easier to manage
300 thin client terminals and 30 CAD workstations than 330 standard PCs. Businesses,
schools, colleges and almost every industry can benefit from thin client technology.
What about the costs?
It doesn’t matter if you are putting in a new batch of machines or replacing old
ones, thin client technology should give you significant savings. The chart below
shows the effective cost of adding between 10 and 100 new PCs and terminals to a
network including a basic server. The chart assumes a cost of £300 per PC and £200
per thin client terminal. The thin client terminals are a fixed cost; the PC cost
will vary depending on their specification – a basic PC cost is used for illustration
of the minimum cost savings.
No ongoing management costs are taken into consideration with either of the solutions
but these are significantly lower with a thin client system!
Everything is centralised with the thin client system, i.e. upgrades and applications
are installed on the central server once and automatically each thin client terminal
gets a copy. Hence the day to day management costs of the thin client system are
Another major benefit of a thin client system is that you can use more than one
central server to increase the server availability and share the workload across
a ‘farm’ of servers. With two thin client servers if one were to fail the users
are able to continue their work on the remaining server. There is no limit to the
number of thin client servers that you can link into a ‘farm’ together.
Over time the cost savings increase further: the terminals themselves have a useful
life span of 2 to 3 times that of a standard desktop PC and therefore need to be
replaced much less frequently.