I've read about SQL Server buffer cache and various discussions about tuning it, using the Maximum and Minimum Memory settings. But I have a doubt: the operational system has a disk reading cache too. If I use a Maximum Memory way below the available operational system memory, would the operational system cache the disk pages and make its next retrieval faster?
From this KB:
In other words SQL Server (engine) disables OS disk caching, so lowering the amount of memory SQL Server uses will leave more memory available to the OS and will not be used for windows caching. SQL Server's buffer cache is much more sophisticated and suited to the job of caching sql server data then windows disk read caching.