Heap size should be set to 4000 (MB) for both initial and maximum size, presuming a load of 800 users. If your load is smaller you may be able to reduce the heap size proportionately.

Optional Recommended Arguments

There is a recommended argument that can help tune performance. Specify the following argument in the command line:

-Xgcpolicy:gencon -Xmn1000m

If you are running a heap size different than 4000 then you should adjust -Xmn correspondingly to stay at 25% of the heap size.

Another argument relates to Collaborati Spend Management (CSM). The syntax of the argument is:

-Dcollaborati.connection.readTimeout=<number of minutes>

Default value is 60 minutes and it is rare that you would need to change it. If you anticipate dealing with unusually large volumes of data through CSM, you should set this argument to a larger value, to avoid timeouts during synchronization. An example of large volumes would be timekeeper counts of 2000 or more.