[Freedos-devel] MS DOS versus slowdown

[Alain <al...@po...>]

I received this in PVT, but I believe it may interrest...

Hi Johnson, MS DOS does not use the HMA for BUFFERS as far
as I know, so indeed: The 10-20% slowdown if DOS=HIGH should
not happen on MS DOS. But on the other hand, buffers in HMA
give you a lot more DOS RAM free :-).

The real problem is the UMB slowdown, and Alain tells that
things get VERY slow with DOS=UMB. So if MS DOS avoids that,
it would be interesting to know. Or maybe using MS EMM386
or MS HIMEM or MS whatever is the point here? I do not think
that the kernel causes UMB slowdown - looking at our kernel
design, I think that only 5-15% slowdown should happen with
UMBs.