Client is sitting next to me and asking for reasons...
Tell him that SQL is designed to use all the memory it is allocated and that using 90% of the memory is a good thing.
You don't have a problem (except for a client that appears to refuse to believe you). you are seeing normal, expected, intended behaviour.
It's like saying, "My car goes fast when I press the accelerator, what's wrong?"
Now, we've repeatedly mentioned max server memory, and a chapter in a book all about memory, so by now you should be in a good position to know exactly what (not) to do in this situation.
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)SQL In The Wild
: Discussions on DB performance with occasional diversions into recoverability
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