About the High Performance Option

Note The following applies to Meridian 32-bit editions when run on a Windows 32-bit operating system only. For information about running Meridian 32-bit and 64-bit editions on a Windows 64-bit operating system, see BlueCielo support for 64-bit Windows operating systems in the Meridian Enterprise knowledge base.

The Meridian High Performance Option (HPO) is a configurable performance enhancement available for use with large vaults or other configurations where server performance is less than adequate even after the Windows configuration and server hardware have been optimized. The HPO enables Meridian to use extended memory for its vault database caches beyond the Windows 3 GB limit (4 GB for 32-bit Meridian components run on 64-bit editions of Windows). The HPO is only useful on computers with more than 4 GB of physical memory installed. When properly configured, the HPO can make more lower memory available for additional vaults, more documents per vault, or more concurrent users. We recommend that the HPO be used when the total size of all vault caches plus the memory required for the expected number of user sessions exceeds 2 GB (or 3 GB if the /3GB switch is enabled).

The Meridian HPO works similar to Windows virtual memory. That is, instead of attempting to cache vault databases entirely in lower memory, the HPO caches them in extended memory. A small amount of lower memory is reserved for caching changed vault data before writing it to disk. When data will be changed that does not yet exist in lower memory, it is first read from extended memory. When data in lower memory is no longer needed, it is cached in extended memory until it is needed again. Any particular vault data only resides in either lower or extended memory at one time but can be read from either location.

In order to use the HPO with 32-bit editions of Windows, the server must have the Microsoft Physical Address Extension (PAE) enabled, which is supported by the Enterprise and Datacenter editions of Windows Server. The PAE option allows 32-bit versions of these operating systems to address over 4 GB of memory up to a maximum of 128 GB depending on the particular Windows version. For information on enabling the PAE option, refer to Intel Physical Addressing Extensions (PAE) in Windows 2000 on the Microsoft Support website. Additional information on PAE can be found in Physical Address Extension - PAE Memory and Windows on the Windows Hardware Developers Central website. The 64-bit editions of Windows Server do not require any special configuration in order to use the HPO.

Note Windows normally uses extended memory to cache data before writing it to virtual memory on disk. However, Windows does not do this if a Hypertrieve database is stored on a network device accessed by a UNC location instead of a drive mapped to the Meridian application server. In that case, Windows assumes that the data could be modified by other users since it does not reside on the local computer. Therefore, consider enabling the High Performance Option even with moderate size vaults if performance seems inadequate in such a configuration. For more information about vault storage space requirements, see Understanding document storage space requirements.