Max Server Memory Matrix

Have you ever wondered how much memory to assign your SQL Server instance?

Here’s a script to do it for you. If you want to understand how it works, read on!

This is based on an algorithm that Jonathan Kehayias wrote in his book, Troubleshooting SQL Server: A Guide for the Accidental DBA, and repeated in his blog post, How much memory does my SQL Server actually need?.

In broad strokes, you should give the operating system the following (quoted from the blog post):

• 1 GB of RAM for the OS
• plus 1 GB for each 4 GB of RAM installed from 4 – 16 GB
• plus 1 GB for every 8 GB RAM installed above 16 GB RAM

Whatever is left over, can go to your dedicated SQL Server instance. If you’re running anything else on the server, you will need to adjust the Max Server Memory downwards accordingly.

Keep in mind that some internal and peripheral devices may have additional memory requirements (see the blog post above).

Please feel free to use and share this link.

** Standard Edition supports a maximum of 64 GB RAM, for SQL Server 2012 and below. SQL Server 2014 Standard Edition and higher supports up to 128 GB RAM.