Sound advice from Glenn Berry and I'm not aware of any good reasons not to follow it.
Restricting SQL Server's memory use may hurt performance in some cases, but allowing it to "strangle" the OS and get into fights with Windows will hurt worse and can cause far more serious problems. So, basically, if you think your suggested max memory setting is too low for your SQL Server, you should set it anyway and then order more memory. 🙂
Vegard Hagen
Norwegian DBA, occasional blogger and generally a nice guy who believes the world is big enough for all of us.
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Blog: Vegards corner (No actual SQL stuff here - havent found my niche yet. Maybe some day...)