Optimizing Conventional Memory

The methods for conventional memory management under Windows 98 are the same as for MS-DOS 6.x:

In Config.sys, load himem and emm386 (using either the ram or the noems switch), and load any required real-mode drivers and applications using devicehigh or loadhigh statements.
Remove as many real-mode drivers and TSRs from Config.sys and Autoexec.bat as possible, and instead use new protected-mode drivers and applications created for Windows 98.
Use buffershigh, fcbshigh, fileshigh, lastdrivehigh, and stackshigh to ensure that reserved memory is taken out of the upper memory area.
Do not load smartdrv in your configuration files, except in configuration files for an application that you run in MS-DOS mode. Windows 98 uses an improved method for disk caching, so loading smartdrv typically wastes memory that could be used by MS-DOS-based applications.

You can still run the MEMMAKER utility provided with MS-DOS 6.2x to load real-mode drivers in the upper memory blocks (UMBs). This utility is available in the Tools\Oldmsdos directory on the Windows 98 compact disc.

For more information about MS-DOS mode and other configuration issues related to MS-DOS-based applications, see Chapter 25, "Application Support." For specific information about MS-DOS memory settings, consult the Microsoft MS-DOS 6.2x Technical Reference or other books on MS-DOS memory management.

MS-DOS Mode and Performance

Do not assume that running an MS-DOS-based application in MS-DOS mode provides better performance. When an application runs in MS-DOS mode, Windows 98 and all of its protected-mode drivers are unloaded, so the application is running in real mode with exclusive use of the computer’s resources.

Although this might help with a few applications that otherwise cannot run under Windows 98, it does not benefit performance overall, because the application does not get the benefit of protected-mode drivers, VCACHE, 32-bit disk access, and so on. Also, real-mode device drivers must be loaded, reducing the amount of conventional memory available to the application.