a few years old now- but I was wondering the same. 100 means 100% but what 0 meant I think has changed. Certainly back in the early Sybase days I think that 0 meant (something like) 100% for clustered, 80% for non-clustered (or the other way around) - this was something "built in" as a default. Not sure if SQL Server was the same and/or if Sybase has now changed it, but I guess that's the core of the original posters question and something I was wondering myself...