Oddbjørn Sæther wrote:

We plan to install FreeSurfer on a Linux server (probably SuSe 9),

Unless you have a compelling reason to run an old version of SuSE (version 9 was released in October 2003), I would strongly recommend using the current version, 10.1. Older versions of mainstream distros will require increasing amount of maintenance to simply run current and new versions of FreeSurfer.

How much memory will this "server" have? How many processors? These specs are probably critical.

and run from Windows PCs via FreeNX/NXclient.

1. Will that work?

It *might* work. I have run FreeSurfer graphical apps with remote display to Windows XP running cygwin. Personally, I would not recommend doing this - remotely displaying the graphical FreeSurfer tools on any platform can be painfully slow, even on a fast local 100MB/s LAN.

I don't know much about the FreeNX X server (Windows or otherwise). In general though, of all the platforms to use, Windows is probably the most difficult choice to remote display to. Other than display issues, Windows machines would require a non-trivial amount of setup and maintenance to seamlessly integrate with a Linux box running FreeSurfer.

2. What system requirements is advisable with 3-6 users?

What do you mean? FreeSurfer is quite memory and resource intensive. It is not a good idea to run more than one instance of any FreeSurfer tool on any single machine. If you are planning to install FreeSurfer on a single "server", and have all your users remotely access this single server to run tools and graphical apps, you will no doubt very quickly bring the server to its knees.

In general, each FreeSurfer stream requires a single dedicated processor and about 2GB of memory. So if you want four people to all use the same machine, you'd need a machine with four processors and at least 8GB of RAM.

3. Is 3D graphics cards necessary on the Windows PCs (or how does this

work)?

Whatever the client OS, 3D graphics cards are necessary if you want to use the graphical apps.

While the setup you describe might work, you might find yourself quickly frustrated with performance issues, both on your single server, and quite probably on your Windows clients.

The graphical FreeSurfer apps in particular are not specifically designed to run in a client/server model, but should be run locally. While a lot of the backend computational tools can easily be dispatched to a different machine, you probably won't want to run more than one stream on any one box/processor. Certainly three, or even two people running a reconstruction stream on a lone server (unless it is a very high end machine) would probably not be a good idea.

In fact, the best recommendation would be to install FreeSurfer locally on each machine that you want to use. If you cannot replace your Windows installations with Linux on the client PCs, you might want to think about dual-boot or vmware-type options. If this is not viable, the best case would be to get dedicated Linux (or Mac OS X) machines to use FreeSurfer.

Cheers -=R