Optimizing Conventional Memory

The methods for conventional memory management under Windows 95 are the same as for MS-DOS 6.x:

• In CONFIG.SYS, load himem and emm386 (using either the ram or noems switches), 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 95.
• Use buffershigh, fcbshigh, fileshigh, lastdrivehigh, and stackshigh to ensure that reserved memory is taken out of the upper memory area. For information about these commands, see Appendix A, "Command-Line Commands Summary."
• Do not load smartdrv in your configuration files, except in configuration files for an application that you run in MS-DOS Mode. Windows 95 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 (UMB). This utility is available in the OTHER\OLDDOS directory on the Windows 95 compact disc.

For information about MS-DOS Mode, and other configuration issues related to MS-DOS – based applications, see Chapter 22, "Application Support." For specific information about MS-DOS memory settings, consult the Microsoft MS-DOS 6.2 Technical Reference or other books on MS-DOS memory management.

Tip for MS-DOS Mode don't assume that running an MS-DOS – based application in MS-DOS Mode provides better performance. When an application runs in MS-DOS Mode, Windows 95 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 95, it does not benefit performance overall because the application doesn't 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.