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You may experience performance problems when you are working with items in a large .pst file or in a large .ost file in Outlook 2007
Article ID: 932086 - View products that this article applies to.
Microsoft Office Outlook 2007 momentarily stops responding during typical operations. This includes when you read e-mail messages, move e-mail messages, or delete e-mail messages.
These symptoms are most noticeable during mail delivery or during synchronization. These symptoms become more pronounced as store size increases. They are more likely to occur when the size of the .pst file or the size of the .ost file approaches 2 gigabytes (GB). Additionally, they are more pronounced in a very large .pst file or in a very large .ost file that is 4 GB or larger.
Note When you perform the same operations in earlier versions of Outlook, the same performance problems do not occur if the .pst file or the .ost file is large.
To accommodate new features, Outlook 2007 introduced a new data structure for .pst files and for .ost files. In this new data structure, the frequency of writing data to the hard disk increases as the number of items in the .pst files or in the .ost files increases.
Note You cannot create a .pst file or an .ost file without this new data structure.
To resolve this problem, install the update that is described in the following article in the Microsoft Knowledge Base:
933493Update 933493 is available to improve the general responsiveness of Outlook 2007 during common operations. These operations include reading, moving, deleting, and downloading e-mail messages for users who have large mailbox files (.pst files and .ost files) that are stored on their computers. From a technical perspective, this update optimizes the pattern in which Outlook 2007 writes to a large .pst file or to a large .ost file. This results in a reduction of disk access.
(http://support.microsoft.com/kb/933493/ )Description of the update for Outlook 2007: April 13, 2007
This update for Outlook 2007 is part of our continued commitment to improving our customers' product experiences. We are aware that some customers have encountered performance issues when they run Outlook 2007. This update incorporates several performance improvements. This update is designed to do the following:
You can also use one of the following methods to resolve or minimize this problem.
Video: How to reduce the .pst file size for Outlook
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Method 1: Reduce the size of the Exchange mailboxIf you reduce the size of the Exchange mailbox, the size of the .ost file will also be reduced. To reduce the size of the Exchange mailbox, do one or more of the following:
Method 2: Use an online mode profile instead of a cached mode profileCached mode profiles use an .ost file to store the mailbox locally on the hard disk. If you have a large Exchange mailbox, you will have an .ost file that is even larger. For example, if the mailbox size is 350 megabytes (MB), the .ost file size can be 475 MB or larger.
Method 3: Split your large .pst file into several smaller .pst filesOutlook 2007 does not have a built-in function to split a .pst file into multiple .pst files. Therefore, you have to use one of the following steps to split a large .pst file:
Method 4: Use a filter to restrict the items that you synchronize from Exchange to your .ost fileTo configure a synchronization filter on a specific Exchange mailbox folder, follow these steps:
If you use a synchronization filter, you can view the items that are not synchronized with the .ost file either by using Microsoft Office Outlook Web Access or by using an Outlook client that is configured to use online mode in an Outlook profile.
If you use a portable computerIf you are using a portable computer, you may experience these problems sooner than you would on a desktop computer. This occurs because hard disks on portable computers are generally slower than hard disks on desktop computers. The performance problems are directly related to hard disk speed. If you add more random access memory (RAM) to a computer, there is no effect on this problem.
For more information about Outlook .pst files, click the following article numbers to view the articles in the Microsoft Knowledge Base:
(http://support.microsoft.com/kb/830336/ )The .pst file has a different format and folder size limit in Outlook 2007 and in Outlook 2003
832925Note The registry path that is used in article 832925 is for Outlook 2003. For Outlook 2007, use the \12.0 path instead of the \11.0 path that is mentioned in the article.
(http://support.microsoft.com/kb/832925/ )How to configure the size limit for both (.pst) and (.ost) files in Outlook 2003