By default, Enterprise Vault stores the compressed text or HTML versions of archived items. This lets users search for items and preview their contents before retrieving them. If you have no requirement for users to search on or preview the contents of items, you can improve performance by turning off content conversion.
To control content conversions
Edit the registry on the computer that is running the Enterprise Vault Storage service.
Edit, or if necessary add, the following DWORD value:
HKEY_LOCAL_MACHINE \SOFTWARE \KVS \Enterprise Vault \BypassConversions
Give BypassConversions a value of 0 to perform content conversions or 1 to turn off content conversion.
Stop and restart the Storage service to make the change take effect.