You may experience poor performance when you use many SetCell calls in Excel Services

When you use many SetCell calls in Excel Services, you may experience poor performance.

To resolve this issue, follow these steps. Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:

1. Apply hotfix 955144. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
   955144  (http://support.microsoft.com/kb/955144/ ) Description of the Excel Services in SharePoint Server 2007 hotfix package: July 11, 2008
2. Set the WebServiceSessionCloningDisabled registry entry. To do this, follow these steps:
   1. Click Start, click Run, type regedit, and then click OK.
   2. Locate and then click the following registry subkey:
      HKEY_LOCAL_MACHINE\Software\Microsoft\Office Server\12.0\Excel Services
   3. On the Edit menu, point to New, and then click DWORD Value.
   4. Type WebServiceSessionCloningDisabled, and then press ENTER.
   5. Right-click WebServiceSessionCloningDisabled, and then click Modify.
   6. In the Value data box, type 1, and then click OK.
   7. Exit Registry Editor.