The possibility that Plastic SCM 2.0 introduces of having multiple servers at the same time results on a remarkable performance increase and greater configuration flexibility.
Users must be aware that a Plastic SCM server manages two different concepts: repositories and workspaces. A repository is a database where all the versioned objects are stored. A workspace is an area in the developer’s disk where a copy of a project stored in a repository is downloaded so that the developer can work with it locally.
In the default configuration a Plastic Server manages both repositories and workspaces, but the system is flexible enough to allow different layouts. Different repository and workspace servers can be configured to cooperate enhancing overall system performance, reducing network usage, distributing storage and balancing CPU load.
The following images shows a scenario with multiple workspace servers working with a single repository server:

You can find more information on this feature if you have a look at our Independent Workspace and Repository Servers Whitepaper or if you go to chapter 6 on the Admin Guide.