June 2, 2003 at 5:53 am
I have a server machine with 6GB of RAM, with Win2K Advanced Server and SQL2K EE. I have to use /3GB and /PAE switches in the boot.ini file of the OS in order to take full advantage of the physical RAM. From SQL server I have to enable AWE in order to address this much RAM. Now according to Microsoft, with this much RAM, OS keeps for itself 2GB RAM, and the rest then is available for the application. With the help of /3GB switch, OS releases 1GB RAM out of its 2GB for the applications. So according to this theory, with my settings, I should have 5GB of RAM available (out of total 6GB physical RAM). But while enabling AWE, if I set the "max server memory" to 5.5GB, it is allocated to the Server leaving only 0.5GB for the OS. Can any body explain why is this contradiction???
I know that even Microsoft says that if we won't set the max server memory while enabling the AWE, AWE then will take all the available memory leaving behind only 128MB for the OS. This is a complete contradiction to the statements which Microsfot gives while explaining /3GB and /PAE switches.
June 5, 2003 at 8:00 am
This was removed by the editor as SPAM
June 10, 2003 at 3:59 pm
Hameed,
Keep in mind that the /3GB and PAE switches apply to other Microsoft applications in addition to SQL Server EE. For example, Microsoft Exchange 2000. That is probably why you are seeing contradictory statements.
Bottom line is this:
In your configuration, SQL Server will grab all but 128 MB of RAM (reserved for the OS) unless you specify otherwise by using the 'max server memory' switch. The reason for this is that AWE memory cannot be dynamically managed in the same way that memory is normally managed in SQL Server. So when SQL Server starts it will grab all but 128 MB and will not release any of it until SQL Server is turned off.
I have a production SQL Server with 8 GB of RAM. My max server memory is set to 7168 (about 7 GB) of RAM; allocating 1 GB to the OS. This is a dedicated SQL Server box, so this configuration works really well.
Hope this helps.
wavie davie 🙂
Viewing 3 posts - 1 through 2 (of 2 total)
You must be logged in to reply to this topic. Login to reply