Subject: RE: DJGPP and RAM disk
To: djgpp AT sun DOT soe DOT clarkson DOT edu
Date: Wed, 22 Apr 92 9:16:57 METDST
From: Luca Collofra <collofra AT di DOT unipi DOT it>
Status: O


| Since I've noticed that DJGPP is HIGHLY disk-intensive, I tried setting up a
| RAM disk for swapping and for the include files.  Unfortunately, it starts to
| compile (cpp) and then hangs for no apparent reason.  I'm running under DR-DOS
| 6.0 and am using the VDISK.SYS utility included with the program.  I'm also
| using QEMM 6.01 as a memory manager.
| 
| Is it possible to run DJGPP while swapping to a RAM disk?  If so, has anyone
| who experienced the VDISK Blues found a cure for them?
| --
| 
| Laurent Duperval
| duperval AT ere DOT umontreal DOT ca
| duperval AT jsp DOT umontreal DOT ca


I know a solution to this question/problem just because I asked it to DJ
himself some monthds ago.
He said to me that it's better to leave as much free memory as possible to the
compiler instead of trying to speed it up with caches/ram-disks.
The reason is that the DJGPP makes a heavy use of virtual memory, i.e. disk
paged memory. So, the more free memory you have, the less frequently DJGPP
swaps the RAM onto the disk!

Personally I'd preferred a disk cache to a virtual disk because by doing so
you'd let the cache program to chose the most used files to be in RAM!

By the way, I encountered your same problem with Norton Cache 6.01 and
QEMM 6.02. My system (an IBM PS/2 55sx) used to hung up after a while when
using the cache. The problem arises from an incorrect timing interaction
between the N-Cache and the QEMM386. I just changed the cache program with
the HyperDisk 4.31 that works quite finely with the QEMM! Give it a try, it's
PD/SW !

.---------------------------------------. .-----------------------------------.
| Vincenzo (Enzo) Romano                | | Maybe computers will never become |
| collofra AT di DOT unipi DOT it                  | | as intelligent as Men, but surely |
| Dept. of Computer Science, Pisa ITALY | | they'll never become so stupid.   |
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