Thin Client

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A thin client (english thin client) and lean ( lean ) or slim client ( lean client ) called, is a computer or computer program that relies heavily on the help of other computer or its server to meet its actual computer tasks. This is in contrast to the fat client (english fat client ), which is built by its hardware and software so that he can even do its own tasks. Other manufacturers often dependent designations are as follows: Cloud Client, Zero Client, Universal Desktop, Clever Client and more.

These thin clients are useful when fat clients are too expensive, as they consume either too much computing power or power for the tasks assigned to them. Examples of thin clients are computer terminals or computers running with stripped-down operating systems.

Thin client workstation

For the operation of a thin-client application less hardware and less computing power is needed. A thin client represents only the user interface, the data processing is performed by a server. Examples of thin-client applications are Web browsers or applications to access Terminal Server. When using a terminal server, all entries with a specific protocol (X Window System, Remote Desktop Protocol (RDP ), Citrix XenApp ICA ) is sent to the terminal server. Since 2008, virtualization technologies such as Hyper- V, Citrix XenDesktop and VMware View has gained importance, these represent another possible use for thin clients and now allow a very individual and central provision of work environments.

On the server or virtualized desktop the inputs are processed and the output is sent back to the client that it only needs to show. The current generation of Terminal Server and virtualization solutions also allows the use of hardware through a printer and also works with optimized methods for playing audio and video data.

Typical thin client operating systems are based on Linux, Windows CE, Windows Embedded Standard (Win32) or Windows Embedded 7 and by writing filters from tampering by users or viruses and the like protected. Some manufacturers also allow the central provision of system modifications in order to install device drivers, for example, wallpapers etc..

Special devices are provided for the operation of the thin client applications, often referred to as a thin client. For these thin clients there is no clear definition. As a rule, including desktop computers without external mass storage (hard disk, CD-ROM drives ) are understood, which can be configured and managed via a central management software.

Conceptual history

The term is derived from the thin client Sun Microsystems. The Sun Ray was called a thin client. On the Sun Ray server the RDP protocol from Microsoft is implemented, and the finished screen contents are sent to the Sun Ray appliances.

Manufacturers such as Hewlett -Packard and Wyse have produced microcomputer, they have also called thin clients. In this case, the RDP protocol from Microsoft will be implemented on the devices from a graphical map in screen content. On these devices, runs an operating system and thus these devices are normal computer, but without the hard drive. Subsequently, Sun Microsystems, the Sun Ray devices renamed Ultra thin clients.

Manufacturer of thin clients

According to an IDC study from the year 2006, the global market for thin-client workstation equipment of the company Wyse Technology is (2012 acquired by Dell ) and Hewlett -Packard dominates. These two companies have a market share of over 70%. Other manufacturers of thin clients are Sun Microsystems, IGEL Technology (market leader in Germany ), Chip PC, VXL Instruments, Hako computing, Rangee, Devon IT, Athena or Statodesk (formerly LISCON ), Fujitsu Technology Solutions, LuniLogic and others.

Pros and Cons

The biggest advantage of thin clients against fat clients is the simpler operation. On the thin clients only the software that is needed for access to centrally -powered applications running. This basic software can be independent of the applications that are actually used to operate uniformly. One approach is the use of configuration images, which, after they are created, are distributed to the thin clients to be configured. This also enables a very simple management through centralized or distributed control systems. In addition, are often more cost-effective thin clients by the lack of moving parts. Then there is the greatly reduced administrative burden, since a virtually unlimited number of thin clients can be managed by simple assignment of configurations. The rapid switching on and off of applications for the end user performs particularly at distant clients and lengthy installations to a significant service advantage. Also a considerably lower power consumption at the most thin-client model is the rule. For example, requires a standard thin client 10 to 20 watts of electrical power, standard multi-core CPUs without peripherals are compared alone at about 40 to 120 watts. Indirect burden Thin Clients air conditioners in office buildings less because less waste heat than standard desktop PCs. Has to be considered here, although the higher income or consumption of the corresponding server system, but this does not diminish the benefits usually only to a small extent.

The useful life of a thin client is an average of seven years, a conventional desktop is used three to four years.

Despite these advantages, thin clients are currently being used relatively little. In 2008, 27 million desktop PCs and thin clients, 1.2 million were sold in Europe. This is due to the disadvantages that come with using thin clients with it: graphics -heavy applications can be customized with many client / server solutions do not perform useful if the network the amount of data can not process fast enough or when applications require accelerated graphics cards to thin clients are rarely available. Most applications are programmed for fat clients. Often the operation of applications on servers is prohibited by license conditions and requires additional and often costly licenses of the software vendor, which will also not be granted in any case. Thin clients can not be used without a network connection. For mobile users are therefore only of limited use.

New technologies on the server side and the increasing better virtualization technology, it is foreseeable that the market share of thin clients will increase steadily. This will ultimately favored by rising cost pressures and increasingly complex work environments in the enterprise. Thus, the thin client is in standardized work environments with a high level of job number is a real alternative to the normal PC.

Zero Clients / System on Chip

For some time the term Zero Client is used by some manufacturers, but these devices are attributable for the most part the group of thin clients. The idea here is primarily the potential buyers a limited function (eg only one possible service like Citrix XenDesktop, VMWare View or IBM Virtual Desktop for Smart Business ) with a simple, primitive and more or less secure management (eg to make. using DHCP options) tasty. The definition is flexible depending on the manufacturer and it is possible that the term " Zero Client " will sooner or later replace the term "thin client". So you can, even despite contrary claims of the manufacturer, in nearly every Zero Client both a firmware (Linux -based or fully own OS), RAM and find a CPU. The firmware was, however, limited to a minimum range of functions. Fast boot times can be achieved, inter alia, a change to suspend mode and awaken so at the user the impression that it is a " zero client " with short start times.

Since Zero Clients are limited usually to a technology on the server side, you have to register as a client be aware that you can long-term commitment to a solution and compared to a "normal" thin client is not in demand, the solution on the server side simply can change. It also remains to be seen how the medium term, the update policy of the manufacturer will be, for example, in large update on the server side; this is due ( depending on the model currently up to 128 MB ) in a very limit Bankrupts space for firmwares.

The concept of system on chip is also now called by various manufacturers, however, these systems are also covered by the term Zero / Thin Clients. The system-on- chip are for example widespread on mobile devices and combine the main chips such as CPU, GPU (including video decoder), network chip and chipset on one chip. Also new is that here some other architectures as the dominant on the desktop x86 architecture such as the ARM architecture used and the operating system which does not originate from the desktop and are based for example on Android ( operating system). Here advantages of the ARM system can be used. They are designed very power efficient and cost-effective. There are also x86 SoC, but because the operating system of the client by the server operating system is independent, there may be an open competition between architectures without the software used by the user are orginär run on the architecture must.

Future

In many areas, especially as regards the use of USB devices, multimedia and graphics-intensive applications, the disadvantages of thin clients are gradually smaller or even disappear. Current extensions / protocols such as Citrix HDX, PCoIP, VMware, Microsoft RemoteFX and esp. already give an idea of ​​what will be possible in the future. The changes on the server side, for example, by plans of Intel, server-side GPU and CPU to merge, and the permanent availability of higher network bandwidth and the need of the user for an easy- to-use system which additionally offers a high level of security will accelerate this trend and open up new fields of application for thin clients.

With further development will reach home and here replace desktop PCs sooner or later more and more thin-client products. Examples that follow this vision, are indirectly in the form of the Apple iPad, Android Tablet PCs and Smart Phones corresponding already exist and are gaining in popularity. In the medium term, one can assume that here under the heading of cloud computing also complete virtual desktops will reach the private user, as also now available for all current server systems relevant clients already available and thus the stage is set.

Favors this development further by rising energy prices and the much easier handling of these devices, for example, if they are centrally maintained on ISP or other provided at an acceptable price.