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Subject: Rebel running (on machines with more than 64MB RAM) slows down by 50%.

Author: Komputer Korner

Date: 10:01:44 11/07/97


The following was Moritz Berger's response to my complaint about the
subject of Rebel slowing down on my machine with 144Mb of RAM.

"Tecra 710 and up support 144 MB fully cacheable memory, I have one
myself (144 MB, successfully used with Linux, NT, 95, Solaris so far).

Rebel's several year old built-in DOS extender doesn't work on systems
with >64MB via DOS himem.sys and emm386.exe, it will refuse to run if
those are detected because it sees some negative amount of available
XMS memory. On those machines you have to run it without memory
managers, this works well on my other 64MB+ machines (at full speed).

On my Toshiba Tecra, Rebel's legacy DOS extender (*without himem.sys
and emm386.exe*) suffers from an unknown bug which will slow down
speed exactly by the same amount as turning off 2nd level cache (but
only on 64MB+ machines!).

The slowdown is always constant, i.e. it doesn't matter how much hash
tables are allocated or how long the search takes.
******* IMPORTANT ******
It does not occur under Windows 95 in a DOS box, which provides memory
services that simulate a <64 MB machine for the affected DOS programs.

=> solution for KK:

If you have 144 MB, just run Rebel (without W parameter, so you will
get 60 MB HT) under Windows 95. Problem solved.
*********
(KK's comment: Moritz, I think you meant that Rebel should be run in a
DOS box within Win 95.  )


solution for me (cause I need the Auto232 autoplayer which only works
under plain DOS):

I installed a 3rd party DOS extender which lets you limited the size
of available XMS memory. Setting this to e.g. 60 MB will make it
compatible with Rebel's own DOS extender. The product I use is called
386Max 8.0, Qemm doesn't offer a similar feature.

Moritz Berger"


The following is Andy Duplain's explanation. The QUESTION IS WHO IS
RIGHT?

"the tag ram used for the caching can only
> serve the first 64MB; putting more than 64MB in, on a system with such
> limitations, is detremental to all software and O/S's I would have
thought.
Andy Duplain"

--
- -
Komputer Korner

The inkompetent komputer

If you see a 1 in my email address, take it out before replying.
Please do not email both me and the r.g.c.c. at the same time. I read
all
the postings on r.g.c.c.

Andy Duplain <duplaina@nospam.bt.co.uk> wrote in article
<63un4b$fgu$1@pheidippides.axion.bt.co.uk>...
> Robert Hyatt wrote in message <63t4g2$tg6@juniper.cis.uab.edu>...
> >Komputer Korner (korner1@netcom.ca) wrote:
> >: The added memory on the Tecra 740CDT is by way of a DIMM module, so in
> that
> >: regard I am ok, but the 2nd point of the inaction of the 256KB L2
cache
> >: when using more than 64Mb bothers me.
> >
> >this I don't know about.  There have been many cases where the chipset
only
> >supported caching the first 64mb, however.  Of course, you will play
hell
> >getting Toshiba to admit this, until you disassemble the machine and
prove
> >it to be true.  Then you get the "tough luck, that was how it was
> designed."
>
>
> I think that's the point Robert; the tag ram used for the caching can
only
> serve the first 64MB; putting more than 64MB in, on a system with such
> limitations, is detremental to all software and O/S's I would have
thought.
>
> KK: send the laptop to me and I will replace it with a desktop P133
w/64MB.
> No additional cost.
>
> --
> Andy Duplain, Syntegra, Brighton, UK.
> *** When replying via e-mail, replace "nospam" with "syntegra" ***



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