Error: 'There is insufficient system memory to run this query' and 'Downgrading backup buffers from 960K to 64K"?
Have you ever observed the error specified above?
Do you need to worry for this issue, yes!
First task to check what are the memory settings on SQL Server, by default they will be DYNAMIC and quite common that they might have set with MIN & MAX settings. If you ever see the above error then another option is to check for active connections & processes that are running at the point of time. Also if the SQL instance is performing lot of external calls such as .DLLs, extended stored procedures such as XP_ and mostly SP_OA methods, also ensure if your application deals with any IMAGE or LOB data. Also the KBA815114 refers that if the memory is fragmented then you would see such an information, which is known as the MEM TO LEAVE area.
Better to check the backup jobs too in order to ensure the disk is not having any major issues, even for a simple transaction log backup jobs. Also avoid running UPDATE STATISTICS on all the tables and choose only required tables that with FULL SCAN operation. This is help the server resources to get adjusted, though this is not recommended I have performed a clear cach by running DBCC DROPCLEANBUFFERS & DBCC FREEPROCCACHE to see whether it crops up again on a live server. Do not run on your live system unless you are sure about your database design and stored procedures that might trigger a huge recompilation that will cause another slow performance.