Re: RAM cache on GS

[dempson@actrix.gen.nz (David Empson)]

Louis Cornelio <cornelio@crl2.crl.com> wrote:

> I have a 4 meg card on a rom 3;
> is there any rule of thumb what to set RAm cache at?

Not too huge and not too small.  :-)

> Does the law of diminishing returns set in at some point?

Definitely.  The RAM cache is mainly used to hold directory information,
not data from files.  It also depends on the device driver actually
making use of it.

In particular, if you have a RamFast SCSI card, then it is not used at
all for hard drive accesses.  It isn't used for 5.25" drives either.

It makes a big difference to 3.5" drives, however, so don't get rid of
it completely.  I think I had mine set to 128KB when I last looked (in a
ROM 3 with 5MB+128KB RAM, Apple HS SCSI card), and that is probably
overkill.

Note that the size for the RAM Cache is a maximum.  If the system runs
very low on memory, GS/OS will start throwing out the cache before you
get an out of memory error reported.

-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand