Microsoft SQL Server database administrators are sometimes responsible of choosing the best license model for their companies. I found myself in a situation where I needed to advice the company which SQL Server License model was the most cost effective. During my research I got information from Microsoft, check the quick reference guide and I also came across a very good and easy to follow blog about the SQL Server License models for SQL Server 2008R2 (http://blogs.softchoice.com/microsoftnavigator/2010/09/17/sql-server-processor-licensing-%E2%80%93-when-does-it-make-sense/). A question that was not really answered in that blog is “When does it make sense to use the processor license model?” In this post I will answer this question based
on Microsoft SQL Server 2008R2 listed prices for the enterprise and standard editions of SQL Server.
When calculating which SQL Server License model is the most cost effective for your company you should take into consideration the following factors:
1- Number of SQL Servers
2- Number of processors per server (not cores)
3- Number of users or devices accessing the SQL Server Database
According to the prices listed by Microsoft) these are the prices for SQL Server Enterprise and SQL Server Standard edition:
From the prices above one can conclude that the software assurance costs around 25% of the value of the license. I realize that to calculate the maximum number of CAL’s one needs for the Server/CAL license model to be the most cost effective, a formula can be used, the formula is:
Maximum number of CAL’s
= (Number of Servers*Number of Processors per server*(license price per processor + softwareassurance processor license) – (license price ServerCAL + software assurance ServerCALlicense)) / (CAL price + CAL software assurance price)
Example:
If you had 20 SQL Servers in your organization, from which 15 servers had 2 processors, 5 servers had 4 processors and you want to use SQL Server standard edition on the 15 servers with 2 processors and enterprise edition on the 5 servers with 4 processors, you can calculate the maximum number of CAL’s like this:
In this example you have chosen software assurance
on all servers
First the 15 servers with 2 processors and standard edition:
(15*2(7171+1793)-(898+224))/(164+41)=1306,33
Then the 5 server with 4 processors and enterprise edition:
(5*4(27495+6874)-(8592+2148))/(164+41)=3300,68
A total of 4607 CAL’s. While the
amount of CAL’s stay below the 4607 the Server/CAL license model will be the
most cost effective.
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