INF: Estimating the Initial SQL Server Memory SettingLast reviewed: July 21, 1997Article ID: Q168697 |
The information in this article applies to:
SUMMARYThe following equation, where 'y' is the sp_configure memory setting in 2-KB pages, and 'x' is the amount of RAM on the computer in MB
y=(.95x-22)*512Provides a way to estimate what the initial SQL Server memory setting should be on a computer that is dedicated solely to SQL Server. You can effectively use this equation on computers that have an amount of RAM ranging from 64 MB to 2 GB. On smaller systems, ratioing the values in the table below will provide a more accurate recommended configuration setting.
MORE INFORMATIONFrom the Systems Administration for Microsoft SQL Server 6.5 Student Workbook, the following data is provided for a start in allocating memory to SQL Server: Physical RAM on a computer dedicated to SQL Server Memory dedicated to sp_configure 'memory' (MB) {x} SQL Server (MB) {y} setting (in 2-KB pages)
16 5.468 2,800 (minimum, not recommended) 24 8 4,096 (SQL Server 6.5 default) 32 16 8,192 48 28 14,336 64 40 20,480 128 100 51,200 256 216 110,592 512 464 237,568Using Excel Linear Regression capability, the last four values can be used to generate slope and intercepts for a best-fit line of the form y = mx+b. In this case, m = .9462 and b = (-22.09). For this purpose, .95 and (-22) will suffice, and the equation becomes y = (0.95)*x-22. Thus, the appropriate SQL Server memory setting in MB is: (0.95)*(the amount of physical RAM on the computer, in MB) - 22. Because the SQL Server memory setting is specified in 2-KB pages (for example, 2,048 bytes) and because 1 MB equals 1,048,576 bytes, the conversion factor from MB to 2-KB pages is (1,048,576/2,048) = 512 (2-KB pages/MB), the following equation delivers is the result: The appropriate SQL Server sp_configure memory setting in 2-KB pages is: (((0.95)*(the amount of physical RAM on the computer, in MB) - 22)*512). That is, y = (.95x-22)*512
Notes
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Additional query words: configure calculation formula
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