I set my SQL Server Max Memory manually to allow the OS enough to operate properly, generally I leave 20% for the OS. SQL will acquire and keep memory as it needs it. To avoid choking the OS use the Max Memory setting.
Thanks for the reply.
But my question really how would I know if I have enough memory in the system.
For example we could have 32 GB and really need 90 GB.
I am looking for a formula or rule on this
I heard that 2-3 Gb per processor but I do not no if this is official or just someone's idea.
I am also wondering how to monitor my memory consumption.
You need to be monitoring for memory pressure to determine if you need more memory. Here are a few places you can review to see how to monitor for that condition: