When I was deciding to use thin clients, I was determined to see if there were any disadvantages to these devices. As this would make it more difficult for me to take the decision to buy thin clients.
What are the disadvantages of thin clients? A thin clients main disadvantages are it’s dependency on other systems like servers and services like networks, that can lead to poorer performance and higher costs. These disadvantages include:
- Network dependency
- Server dependency
- Reduced response times
- No offline working
- High upfront costs
Let’s take a look at the disadvantages of thin clients in more detail in the rest of this article.
1. Network Dependency
The biggest disadvantage of thin clients? Network dependency isn’t just one of the biggest disadvantages of thin clients, it is the biggest disadvantage! Because everything that the thin client does or needs is served across a network, this network is simultaneously:
- a single point of failure
- a huge performance bottlenecks
If the computer network, or the server itself, suffers from latency issues, slows down or even just cuts out entirely then the thin client can either lag or stop functioning completely. In a business that relies on these networks and thin clients across its organisation, this is a massive problem.
Even when a properly configured client can alleviate some symptoms, such as being able to use network optimised protocols like Citrix HDX and VMWare PCOIP, the problem of network dependency will remain.
Added to this the fact that networks are inherently much slower than even the most modest of local hardware, and that the larger the network, the larger this disparity, and you begin to question the wisdom of thin clients to begin with.
Single point failure
Thin clients will tend to only have a single connection to the network, be it either through an ethernet cable from the network port on the thin client, a Wi-Fi connection or LTE (4G, 5G) connection on more advanced thin clients.
Should either of these fail the thin client will not be able to connect to the network, unless it can adopt another connection type. So, if the ethernet connection fails, but Wi-Fi is still available then this could be an option as long as the Wi-Fi itself is still working.
Huge performance bottleneck
Desktop computers will use the network as and when it’s required, while thin clients use the network all the time. When the network is being used more, the thin client could suffer as a consequence.
Due to common work patterns, like working nine to five, people will be coming into the office and logging on to their thin clients. The network traffic generated will cause contention on the network, as more and more thin client devices and other devices on the network compete for resources.
Networks without adequate bandwidth to handle the extra network traffic at peak times like when people are logging on and logging off, will make the thin client user experience unpleasant.
As users who have successfully logged on will be hampered in being able to use their virtual desktops by those trying to logon, more so if it’s a mixed network with thin clients, desktop computers and laptops.
Some older thin clients load up their operating system when they are started up using a Preboot eXecution Environment (PXE). This in itself can overload the network if it isn’t managed effectively.
This practice is becoming less common as most thin clients have their operating system stored on solid state storage like Flash memory.
Thin clients will compete with all the other traffic on the network and when there is a lot of traffic, the thin client experience could suffer. This is especially true of branch offices where the network connections can be lighter than in main offices, and moving data across can saturate the network, ultimately affecting the thin client performance.
2. Server dependency
Let’s have a closer look at the problem of network servers on a thin client system being a single point failure. There are of course many positives with thin client networks, but there is also a very large potential risk here that makes a central server one of the major disadvantages of thin clients.
If the server that the thin clients are connected to goes down, the effectiveness of the thin client is diminished and sometimes negated in its entirety. Resulting in the loss of the session and the worse still any unsaved work the user has.
Even with some of the mitigations in place with some thin client systems, like those using Citrix technology, these may not be as effective as needed. When the server performance starts to deteriorate, the connection can be disconnected, allowing the user to reconnect to a server with more resources.
Citrix load balancing algorithms take care of this by keeping an eye on each of the servers loads in a server farm (also known as a site). However, if the server the user is connected to, freezes and stops responding under load then there’s nothing that can be done to salvage the user session unless the server unfreezes and manages to regain some of its resources.
3. Reduced response times
As the thin client leaves the majority of the data that it requires on the server, it has to call on the server for almost every single change – even something as relatively simple as opening up a dropdown menu may mean a quick trip to the server and back again. However small, these actions have a delay attributed to them.
More traditional clients store and access data locally, to storage devices and hardware they are physically connected to. Data retrieval delays are one of the biggest disadvantages of thin clients, especially on slower hardware and network connections.
4. No offline working
Carrying on from network dependency being a problem, this also equates to not being able to work offline. As when there’s no network connectivity available, the thin client can’t connect to the virtual application or virtual desktops on the remote servers.
With a traditional desktop computer, any network availability problems will still mean the user can work on the applications installed on the desktop computer, albeit more slowly if those applications need to get data across the network.
However, with thin clients, there are no user applications installed on the thin client, as the operating system isn’t designed for this. It’s designed to connect to remote servers and process the screen images of the user interactions sent back and display them on the monitor.
5. High upfront costs
Thin clients themselves may cost less than comparable desktop computers but without additional infrastructure, the thin client is as useful as an underwater hairdryer. The remote servers the thin clients connect to, aren’t exactly cheap and to provide high availability should one fail, several servers need to be purchased.
The operating system the server uses need to be capable of providing virtual desktops and with Microsoft Windows Server editions, Remote Desktop Services (RDS) is available as a feature. These operating systems have a cost, a license cost for the operating system and then a client access license (CAL) cost for each of the users or devices (depending on model chosen) connecting.
RDS by itself doesn’t have the smart high availability features like load balancing, like the Citrix XenApp and XenDesktop technologies have. To enable Citrix technology will also require additional license costs.
For larger organisations, going down the thin client route makes sense but for small ones, it’s a prohibitively expensive cost and it may be better to stick to desktop computers or laptops instead.
What does this mean in real terms?
Well, businesses have to be prepared and be able to react to the worst-case scenario. Regular backups should be a routine activity in any case, but in a thin client environment this practice is even more vital.
Redundant hardware should also be on standby and ready to go should a server go down. With proper preparation and implementation, a network failure can be mitigated, and the damage kept to a minimum. Still, on local hardware, this problem is all but non-existent.
Cost benefit analysis needs to be done at the outset to ensure the thin client benefits are not overstated and opting to use them make financial sense.
Are thin clients worth it?
The traditional desktop computer, and or laptop, is still the most popular option in most businesses but other options in the world might suit certain needs better. The thin client is one such option. While these systems do serve a purpose, the disadvantages of thin clients should not be overlooked.
In essence, a thin client is a basic bare-bones PC that does no heavy lifting itself. Instead, it serves as a remote access terminal connected to a central server. The server handles the workload of several thin clients, including storage needs.
There is a place for these systems, but they may not be right for most situations.
Several other issues would constitute the disadvantages of thin clients. For one thing, businesses will quickly see the need for a fast internet connection where thin clients are going to be used.
Also, the fact that powerful servers are an absolute must because otherwise, you have just wasted your money on a thin client system that won’t function adequately. For all of these reasons and more, very careful consideration should be given before deciding on a thin client system.