Date: Mon, 21 Feb 1994 23:02:37 -0600 (CST)
From: Jorge Fernandez Arnaiz <arnaiz AT redvax1 DOT dgsca DOT unam DOT mx>
Subject: Re: RAM drive
To: Raymond Rosmalen <raymond AT hef DOT kun DOT nl>
Cc: djgpp AT sun DOT soe DOT clarkson DOT edu


On Mon, 21 Feb 1994, Raymond Rosmalen wrote:

> Hi, I've been trying to improve on compilation time
> by making a RAM drive. 
> I have in total 3MB XMS memory from which 1MB is in use
> by SMARTDRV. I made an 1MB RAM drive in XMS memory.
> Next, the TMPDIR varaiable was set to point to the RAM drive.
 [text omited...]

> Did I forget something in setting up a RAM drive or
> is 3MB XMS memory just not enough?
> Or maybe, should I have created a smaller (or larger) 
> RAM drive instead?
> 

I ran some tests in my PC, a 386sx, 20 MHz, no 387, 5Mb RAM
but using 2 Mb in a RAM drive to emulate your 3Mb RAM, and
here is what i got:

Using himem, emm386, no RAM drive
        31.69 s       no   smartdrv         => aprox. 2 Mb XMS
        24.25 s       with smartdrv (1 Mb)  => aprox. 1 Mb XMS

Using himem, emm386, 1Mb RAM drive
        28.19 s       no   smartdrv         => aprox. 881 k XMS
        ----- s       with smartdrv can't run

Using himem, no emm386, no RAM drive
        31.06 s       no   smartdrv         => aprox. 2 Mb XMS
        21.29 s       with smartdrv (1 Mb)  => aprox. 1 Mb XMS

Using himem, no emm386, 1Mb RAM drive
        25.90 s       no   smartdrv         => aprox. 1193 k XMS
       130.19 s       with smartdrv (1 Mb)  => aprox. 169 k XMS !!!

From the above results, you can see that you can get better results
using smartdrv than with a RAM drive asuming you only have 3 Mb RAM.
Also, if you can, you should omit emm386 to get better times.
Obviously when there is not enough XMS, go32 use your disk for virtual
memory and the compilation time grows.

My test program uses aprox. 1152 k of RAM when running cc1.exe. Maybe
you can try the topline option of go32 to better sintonize your
config.sys If you get red numbers, then you should let more XMS
avaible and forget about RAM drives or smartdrive.

Hope that helps...

JORGE



======================================================================
name:     Jorge Fernandez Arnaiz
org:      Instituto Nacional de Investigaciones Nucleares
country:  Mexico, D.F.
p-mail:   Sierra Mojada #447, Lomas de Chapultepec, Mexico D.F.
e-mail:   arnaiz AT redvax1 DOT dgsca DOT unam DOT mx
======================================================================