ROM BIOS Shadowing Not an Advantage with Windows NT

 Last reviewed: March 24, 1997
Article ID: Q92766
The information in this article applies to:
  • Microsoft Windows NT operating system version 3.1
  • Microsoft Windows NT Server version 4.0
  • Microsoft Windows NT Workstation version 4.0

SUMMARY

Some computers provide a ROM BIOS shadowing option. While this feature provides an advantage with Microsoft MS-DOS, it is not an advantage with Microsoft Windows NT.

MORE INFORMATION

ROM BIOS shadowing is the process of copying the BIOS from ROM into RAM and using either hardware or 386 enhanced mode to remap the RAM into the normal address space of the BIOS. Because reading RAM is much faster than reading ROM, BIOS-intensive operations are substantially faster. For example, MS- DOS uses the BIOS to write to the screen; therefore, with ROM BIOS shadowing, directory listings run more quickly.

Windows NT does not use the BIOS (except during startup); therefore, no performance is gained by shadowing. If ROM BIOS shadowing is not used, more RAM is available. With Windows NT, there is an advantage to disabling the ROM BIOS shadowing option.

This applies to other BIOS shadowing schemes as well. Typically the CMOS settings allow the system to shadow any BIOS. This includes the following: 

   System BIOS
   Video BIOS
   Other adapters ROM BIOS (in a given select range)

Additional query words: prodnt win32
Keywords : kbenv ntconfig NTSrvWkst
Version : 3.1 4.0
Platform : WinNT

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Last reviewed: March 24, 1997
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