Significant Quantity of PST Files Connected in Outlook May Slow Performance
CITS recommends limiting the number of Outlook archive (PST) files connected to an Outlook profile at one time to fewer than forty (40). CITS found slow performance issues when profiles have a large quantity of PST files connected in Outlook.
In addition, CITS suggests following Microsoft’s recommendations for managing the size of PST files.
·Up to 5 gigabytes (GB): This size should provide a good user experience on most hardware.
·Between 5 GB and 10 GB: This size is typically hardware dependent. Therefore, if you have a fast hard disk and much RAM, your experience will be better. However, slower hard drives, such as drives that are typically found on portable computers or early generation solid state drives (SSDs), experience some application pauses when the drives respond.
·More than 10 GB: This size is where pauses begin to occur on most hardware.
·Very large, such as 25 GB or larger: This size increases the frequency of the pauses, especially while you are downloading new e-mail. As described above, you can use Send/Receive groups to manually sync your mail.