Mail Archives: djgpp/1999/10/14/20:04:24
Eli Zaretskii wrote:
>
> On Mon, 11 Oct 1999, Rez wrote:
>
> > I don't know about Windows' DPMI, but I did some performance testing of
> > CSWDPMI vs DRDOS7.03's DPMI. BOOM (DOOM clone) ran at the same speed +/-
> > less than 0.1% difference (however it takes quite a bit longer to get
> > thrashy on DRDOS's DPMI). OTOH, BSPv3.0 ran at 10% faster on DRDOS's
> > DPMI. This was reproducible and consistent.
>
> Don't forget that CWSDPMI was written by a single engineer on his
> spare time. Given that, I think 10% of a performance hit, and then in
> some specific cases only, is acceptable.
BSP is a naked textmode DOS app, very CPU-intensive but with very little
display output (a spinner and a few lines of text). Is that of any
significance wrt this case's 10% performance difference?
BTW when I do any sort of performance testing, I always disable cache,
because otherwise you don't really know what influence it had on the
results.
Also I wonder if cache could disguise some program faults. Frex, on my
other boot setup, which has a cache, one program's config file directory
entry gets corrupted when I start the program. I've found if I first
copy the config file from one location to another, then start the
program, the corruption does not occur. Presumably at that point it's
snagging the config file from cache instead of from disk.
~REZ~
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