It all depends how how much data will be in the instances and how active the databases are. I’ve run clustered instances with 3 instances installed on 4 Gigs of RAM.
64bit Windows and SQL don’t take any more RAM than 32bit Windows or SQL.
Without knowing more about the databases and the system load there isn’t a way to tell how much RAM should be needed.
If you can answer these questions I might be able to guide you better.
How large will the databases be?
How much of the data will be active data (accessed by the clients)?
How many clients will be accessing the data?
These questions need to be answered for all instances which will be hosted on the cluster, not just the current one.
Hi, most of our UK clients are now told to spec with 16GB, when new server; it doesnt even cost much! Trial and test it and you will know.