Windows 2000 Terminal Services Printer Redirection Whitepaper

Scalability Test Results

In our test runs on this hardware and setup, we saw relatively little degradation in terms of scalability, as defined in the Terminal Server Scaling and Capacity Planning white paper, caused by enabling printer redirection.

Our testing also showed that scalability was very tied to hardware, applications, and usage profiles, just as it affects scalability as explained in the TS scaling documents for standard user scenarios.

Overall, you can expect to see a 10% degradation of your maximum scale by using printer redirection on your terminal server. This figure is an average and may fluctuate higher or lower in a given scenario depending on usage patterns, applications used, and type and size of data printed.

Explanation of Scalability Performance Results

These numbers generally correlate with the scalability numbers specified in the Terminal Services Capacity and Scaling white paper for Knowledge Worker class users, with the added global loss of total server scale by the cumulative load of printing.

As noted, in the above tests LaserJet class printers were used. Some printer models can have a limiting effect on printer redirection scale; most of these devices fall into the consumer inkjet category. Their device architecture provides only the basic capabilities necessary to position the carriage over the paper. Therefore, all of the rendering work that would be handled by a LaserJet–class printer must be handled by the host computer.

In the situation where one of these devices is redirected, the Terminal Server becomes the host, and additional loads may be seen in the way of incremental CPU or memory loads during printing. How much load they introduce to your environment depends on the complexity of the print jobs submitted to them. Documents with large numbers of graphics or complex combinations of typefaces will increase the load. If you have these devices in your deployment, create a testing methodology to understand the tradeoff between using these devices and your impact on scale as a result of using them.

An explanation of these devices from HP, one of the manufacturers of such devices can be found by searching on “PPA (Printing Performance Architecture)” on their site, or visiting the following link:



http://www.hp.com/cposupport/printers/support_doc/bpd02937.html