Align SQL Server 2005 plan cache size limit to a size similar to that of SQL Server 2000: The maximum size limit of the SQL Server 2005 Plan Cache in RTM and SP1 is significantly larger than in SQL Server 2000. To reduce the SQL Server 2005 plan cache maximum size limit to a size similar to that of SQL Server 2000, the limit for signaling internal memory pressure on a cache is changed from that of SQL Server 2005 RTM and SP1. The following table shows how the maximum limit of the plan cache is determined for each version of SQL Server:
SQL Server 2005 RTM & SP1: 75% of server memory from 0-8GB + 50% of server memory from 8Gb-64GB + 25% of server memory > 64GB
SQL Server 2005 SP2: 75% of server memory from 0-4GB + 10% of server memory from 4Gb-64GB + 5% of server memory > 64GB
For a SQL Server with 32Gb total SQL server memory,
SQL Server 2005 RTM and SP1 cachestore limit will be 75% X 8 + 50% X (32 - 8) = 18GB
SQL Server 2005 SP2 cachestore limit will be 75% X 4 + 10% X (32-4) = 5.8GB
I suppose I was not the only one who thought this was just too much. I love the way SQL Server is self tuning for a great part but maybe it would be nice to allow expert users to configure some aspects themselfs anyway, especially with x64 where memory usage is lifted to a whole new dimension. When looking at the fixlist for Service Pack 2 I am getting more and more convinced to wait for it before installing SQL Server 2005 in large production environments.