Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!sjsca4!molehill!poffen
From: poffen@molehill (Russ Poffenberger)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Program Execution Probe
Message-ID: <1989Dec14.204018.24471@sj.ate.slb.com>
Date: 14 Dec 89 20:40:18 GMT
References: <5945@ubc-cs.UUCP>
Reply-To: poffen@molehill.UUCP (Russ Poffenberger)
Organization: Schlumberger ATE, San Jose, CA
Lines: 31

In article <5945@ubc-cs.UUCP> jalbert@cs.ubc.ca (Francois Jalbert) writes:
>Hi there. I am considering buying a 4Mb extended memory card for my AT. I
>would use it as a huge RAM disk from which I could run PC-TeX. I hope to
>speed up things since using LaTeX involves reading and writing so many
>files. However, I would like to evaluate during a typical PC-TeX run, how
>much time is spent doing disk operations or internal operations. This would
>give me an idea of how much speed improvement should be expected. Of course,
>I would rather do that before buying a card and the memory chips. Is there
>such an utility available from somewhere? I browsed through SIMTEL but 
>didn't see anything applicable. I have a pretty good idea how to write in
>assembly such an utility. Just monitor all the disk related interrupts and
>add up the total time spent there. One could increase the frequency at
>which the timer_tick interrupt is called to improve the resolution. And
>also make sure the frequency at which the original timer_tick routines are
>called is left unchanged. I just know it will take me a day to come up
>with the beast, I'd rather avoid it. Any info would be appreciated. Thanks
>in advance. Francois
>                '


If you are REALLY concerned about speed, you should get a card that implements
both expanded memory. You should then set up a ramdisk in expanded memory.

Expanded memory is generally faster because it doesn't cause the cpu to switch
to protected mode, then have to be reset to get to normal mode.

Russ Poffenberger               DOMAIN: poffen@sj.ate.slb.com
Schlumberger Technologies       UUCP:   {uunet,decwrl,amdahl}!sjsca4!poffen
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