INF: How To Enable Analysis Server to Use 3 GB of RAM (295443)

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By default, the Analysis Server process is limited to 2 GB of RAM, unless Application Memory Tuning is enabled. However, you can only enable Application Memory Tuning on a Microsoft Windows NT 4.0 Enterprise Edition or Microsoft Windows 2000 Advanced Server-based computer. With Application Memory Tuning enabled, the OLAP Server process can use 3 GB of memory.

If Analysis Server is running on the Standard version of Microsoft Windows NT 4.0 Server or Microsoft Windows 2000 Server, you cannot enable Application Memory Tuning. When Analysis Server is run with the Standard version of Microsoft Windows NT 4.0 Server or Microsoft Windows 2000 Server, the Analysis Server process is limited to 2 GB of memory. To enable Application Memory Tuning, modify the Boot.ini file, and then add the /3GB parameter to the ARC path. Here is an example of a Boot.ini file with the /3GB parameter added:

[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(1)\WINNT
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINNT = "Windows 2000 Advanced Server" /fastdetect /3GB
multi(0)disk(0)rdisk(0)partition(1)\WINNT = "NT 4.0 Server Enterprise Edition" /fastdetect /3GB
				

For additional information about Application Memory Tuning, click the article number below to view the article in the Microsoft Knowledge Base: After you enable Application Memory Tuning, you must instruct Analysis Services to use the additional memory, because Analysis Services does not detect that additional memory is available.

IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:
WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

To enable Analysis Services to use 3 GB of RAM, after you enable Application Memory Tuning, follow these steps:

1. On the Taskbar, click Start, and then point to Run. In the Run dialog box, type Regedit.
2. Locate the following registry key:

   HKEY_LOCAL_MACHINE\Software\Microsoft\Olap Server\Current Version

3. Edit the HighMemoryLimit registry value, and then set it to a decimal value that is approximately 2.7 GB in bytes. Do not set this value to the full 3 GB because this does not permit the cleaner thread enough time to react to a low memory situation. This value corresponds to Memory Conservation Threshold.

You can perform additional performance tuning by setting the Minimum Allocated Memory property setting in Analysis Manager to a value of 2047. If you plan to edit the Minimum Allocated Memory property, you must change it before you edit the HighMemoryLimit registry value. After you set the HighMemoryLimit registry value, when you edit the Memory Conservation Threshold or the Minimum Allocated Memory value from the Analysis Manager User Interface, values that are higher than 2 GB are reported as a negative value. If you try to close the dialog box, you receive the following error message:



When this occurs, you must either cancel the operation or set the Memory Conservation Threshold property to a value that is in the range of 1 to 2,047.

With Analysis Services Service Pack 3, you can change memory usage above 2,047 MB by using the Memory Conservation Threshold property. To do this, follow these steps:

1. In Analysis Manager, right-click the Analysis Server, and then click Properties.
2. In the Properties dialog box, click the Environment tab. The Memory Conservation Threshold property is a value under Memory Settings.

For additional information about configuring the Memory Conservation Threshold for Analysis Services SP3, click the following article number to view the article in the Microsoft Knowledge Base: