As indicated before, the application list will usually constrain the choices. Until you have that down, specific platforms are moot. There are good reasons to reject specific platforms if they do not have all the applications you and your users need, and you are not willing or able to perform and support the port. Some platforms give you "the best of multiple worlds." Examples of this are Linux + VMWare, or windows and VMWare. If you are building workstations, remember that you might not get to change the hardware for a number of years, so I would err on the side of performance. This way you are not as unhappy in 2.5 years when the machines are "obsolete". -- Joseph Landman, Ph.D Scalable Informatics LLC email: landman at scalableinformatics.com web: http://scalableinformatics.com phone: +1 734 612 4615