Understanding How To Setup CPU Cache Settings

[Parallel]

I'm hoping people here can help me understand the various cache settings and which areas of memory I want to make cacheable, and which I don't.

This is in the context of a MS-DOS 6.22 & Windows For Workgroups 3.11 involving a Cyrix/TI 486SXLC2-40 (so it's a clock doubled 20/40 situation).

According to the system manufacturer, this is the best way to setup EMM386:

DEVICE=C:\DOS\EMM386.EXE /HIGHSCAN X=A000-C7FF I=C800-DFFF X=E000-EFFF

This is also from the manufacturer:

In a computer system containing 1 Megabyte of RAM
memory, the last 384 Kilobytes of this RAM are called
Shadow RAM and requires special software to be able
to use it. This shadow RAM can optionally be mapped
to the extended memory address range. There are several
factors that influence how this RAM should be mapped.

YES: This setting results in the best speed
performance of the computer, but it
requires use of the LIM EMS driver to
make 256 Kilobytes available as expanded
RAM. This is the recommended setting.

NO: This setting maps 384 Kilobytes of shadow
RAM to extended RAM where it can be used
by application packages written to utilize
it. The speed performance of the computer
is reduced.

As such, I figured it makes sense to set it to "YES".

The options available to me for setting up the cache are:











SMM will not be available as the pins on the CPU are NC on the motherboard.

Any information or insight would be greatly appreciated.