[Freedos-devel] FreeDOS speed tests

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

Hi,

I have made a lot of tests, have lots of figures but it all amounts to this:

1) Without UDMA or LBACACHE, FreeDOS is slower that MSDOS 7.10 by a 
factor of almost 2. This is reasonably consistent in more than one test, 
including rawspeed (see below) and my index creating test.

2) UMB+UDMA is veeery slow, no matter if provided by UMBPCI or EMM386 
2.03. This may be machine dependent. In some way it is a good test for 
EMM386 because there is no signiticant difference in performance between 
the two. This was measured with with rawspeed which was developped by 
the formar mantainer od UDMA, it writes a straight 256Mb file and the 
reads it.

3) UMB being slow does not have a big inpact in my indexing test. This 
was unexpected and it probably is due to having too many random accesses 
to only 2 files, which is probably limited by the drive's rotational speed.

4) LBACACHE makes a dramatic inprovement, but only with BigCache + TUNA 
+ TUNW. Only TUNW brings time from 45s to 22s, both TUNA+TUNW brings it 
to 7s. Very im,pressive. With a small cache ther is no improvement.

5) as a comparison,
FreeDOS all the same exept using smartdrv /x, takes 30s
FreeDOS all the same but NWCACHE (with eric's tuning or not), takes 59s
MSDOS 7.10 + smartdrv /X, takes 23s
MSDOS 7.10 + UDMA2 + LBACACHE (same cfg) takes 7s.

Test machine is a PcChips MB, Semprom 2.2GHz, 256Mb. I will make some 
more tests on older machines.

Alain