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Mail Archives: djgpp/2000/02/29/09:54:55

Date: Tue, 29 Feb 2000 11:14:10 +0200 (IST)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
X-Sender: eliz AT is
To: Kalum Somaratna aka Grendel <kalum AT crosswinds DOT net>
cc: djgpp AT delorie DOT com
Subject: Re: rhide compile..
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On Tue, 29 Feb 2000, Kalum Somaratna aka Grendel wrote:

> I don't think that this will have anydifference because if you have a
> samrtdrv (disk cache) with write caching (delayed writing) enabled, the
> disk writes should be as low as possible (maybe even no disk writes as all
> the temp files as deleted in the end!)

SmartDrv flushes its buffers when a program exits, so it is slower
than a RAM disk.  But it is much more efficient in memory usage.  If
you have enough memory, having both SmartDrv and a RAM disk is the way
to go, as the FAQ suggests.

> > Futhermore as pipes are implemented as temporary files on *DOZE (at
> > least for DOZE programs) this will speed up all commands using pipes
> > as well.
> 
> My above message comments on this.

And because SmartDrv flushes buffers on program exit, a RAM disk is
better with pipes as well.  That's why the FAQ suggests to point
TMPDIR to a RAM disk, if it's installed.

> Using your example if you can allocate 64mb just allocate a 64mb! smartdrv
> with write caching enabled and after the first compile all the other
> compiles will almost certainly be ligtning fast, since after the first
> compile the disk cache would have cached all the gcc.exe and librarys etc.

The problem is that with SmartDrv, you don't have the same kind of
control on what is cached and what's not, it is entirely up to
SmartDrv.

For example, if some program calls the `sync' function, SmartDrv
flushes and empties all of its buffers, and forgets about any gcc.exe
it was caching.

> And there will be more efficient memory usage as there is no need to
> allocate memory as in a ramdisk for the whole tool chain, for how many of
> the tools do we actually use?

If you have enough memory installed, this is not an issue.

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