Sizing an application server is highly dependent on the applications running on the server and how the applications are used by everyday  users.  As a rule of thumb, a Linux application server that provides 1GHz of processing speed and 1GB of user processing memory supports 20 to 25 users (when delivering a KDE desktop); this rule of thumb assumes users are "light users" and not running processor intensive applications.  It is recommended that the user memory requirement include an additional base memory of 1GB to support system overhead.  Thus, in theory, a single server with two 3.0GHz CPU cores and 7GB of RAM would support 120 to 150 users.

To determine the approximate amount of maximum sessions, please proceed with the check list provided below:

•  Do you want to run Linux or Windows sessions? This is an important factor since Windows sessions require much less resources.
   
• Do you want to run GNOME, KDE or single applications sessions? This is another important factor because a full desktop will require more RAM than a single application.
   
• Do you need to run special applications on the desktop, for example a heavy-duty CAD or photo application that could hog down the system?
   
• What is the network speed and capacity that is made available at the site? Slower networks require higher compression, hence you will have a higher CPU load.
   

One or Many Servers?
Deciding whether a few large capacity servers is better than a larger number of smaller capacity servers is always a debate.  Frequently, the decision to choose one approach over the other is a question of risk.

A greater number of servers mitigates lost productivity if a single server fails.  For example, when a single server delivers application environments to 20 people, then only 20 people are affected if the server fails.  On the contrary, when a larger server is delivering applications to 120 users, then 120 people are affected if the server fails.

Even though down-time risk is higher with fewer larger capacity servers, the benefits derived from a fewer number of servers can easily outweigh the risk associated with the larger number of smaller servers.  Larger capacity servers are more efficient.  Less effort is required to deploy security patches, system upgrades, and configuration changes; a greater number of users can share application threads; and overall power consumption is reduced.

Further information is available here: http://www.nomachine.com/AR10B00025 

Users are also invited to check their CPU licensing requirements here: http://www.nomachine.com/AR11B00072