[comp.os.msdos.programmer] Using EMS vs. XMS in TC++

jdb@reef.cis.ufl.edu (Brian K. W. Hook) (01/16/91)

A while ago I asked the best way to arrange 8MB on a 386 for optimum
compile times/program development....well, I had many mixed replies,
and this in turn has prompted more questions from me....

1.  Turbo C++ can use extended and expanded memory.  Which is it better at
using?  Is there a maximum amount that it can use?  I.e. if I could configure
my memory as either EMS or XMS, which would be best?

2.  Would it be more efficient to use Turbo C++ giving it all the XMS that
my system had, or would I actually be better off relegating it to a disk
cache?  (ie. is TC++ better at using XMS than a caching program?)

Brian

boerner@cs.utexas.edu (Brendan B. Boerner) (01/17/91)

In article <26342@uflorida.cis.ufl.EDU> jdb@reef.cis.ufl.edu (Brian K. W. Hook) writes:
>2.  Would it be more efficient to use Turbo C++ giving it all the XMS that
>my system had, or would I actually be better off relegating it to a disk
>cache?  (ie. is TC++ better at using XMS than a caching program?)

Offhand I'd say that you want to try to balance between the two.  If
you have a write-through cache, then everytime TC++ swaps using VROOMM,
you get a disk hit.  If you instead gave that 512K or 1024K to TC++,
then it could get by without writing.  However, you still want a cache
of some size to cache header files and what not (unless you have an IDE
disk - I was told by Swan Tech support not to use the cache program
that came with my Swan 386SX since it is meant for their customers who
order non-IDE drives.  He said that IDE had a 64K cache and coupled
with the speed of the drive a cache was unnecessary).

Brendan