Mareike,
since LabVIEW is multithreading (version 5.0 and higher) it can take advantage of multi-processor boards.
At NI Week 2000 there was a presentation about mulit-processor. The presentation includes some resource links and shows a graph about the runtime performance increase.
Hope this helps
Roland
PS: Here is the link to the presentation:
http://zone.ni.com/devzone/learningcenter.nsf/03f7c60f17aad210862567a90054a26c/a0fd709b9195b8bb862569330074c6de?OpenDocument
