SQL Server Performance Question

I’m looking for a “Best Guess” from DB Admin kind of guys.

My company develops – sales and supports a high end accounting software package.

We lease two servers from a data center to host the DB’s for some of our clients. The servers are single Xeon quad core, 4 gigs of ram and have 15k rpm SAS drives.

The servers are currently running Windows Server 2003 and SQL Server 2000.

Since Win 2003 is ending it's lifecycle this summer we're going to be upgrading the machines to Win Server 2012 and SQL Server 2008.

Ideally, we'd like to put all the databases on one machine but we're concerned about the overall impact on performance of the software since it is a bit of a pig on resources.

Currently each machine has 20 users hitting it. Our accounting software is installed on the local clients machine which intern access databases on the servers.

The new machines will have at least 8 gigs of ram if not 16. And I'm uncertain if we'll continue with the faster SAS drives.

The databases are generally considered small in that they don't exceed 1.5 gigs in size.... And we use Crystal Reports Viewer to run reports.

Any and all feedback would be welcomed.

I guess each machine as multiple disks and you separate db data files, log files and tempdb already. For sql version, I'll go for sql2k8r2 at least because sql2k8 doesn't work well with numa.

Thanks for the reply. Actually, each machine only has one drive.

Each machine has four databases for four different clients. Each db does have it's own SQL user to aid in security.