[comp.sys.mac] RAM Cache Setting

thewho@portia.Stanford.EDU (Derek Fong) (01/10/90)

Hi everyone!

Does anyone know what RAM Cache settings optimize the speed of the Mac.
I can't seem to tell.  I've heard stories that you get best results
with 1/4 of your RAM as part of the Cache.

I have a Mac SE/30, 5 MB of RAM.  I currently have it set to 384K.  It seems
okay, but is that too much, and would I get similar performance from only
128K?  Also, does the optimization depend on whether you are using
Finder or Multifinder?

Has anyone out there tried the latest Virtual 2.0.  Is it reasonably fast?

Thanks in advance.  If you can, please reply via email.

--Derek Fong
fong@cive.stanford.edu
thewho@portia.stanford.edu

brian@padouk.ima.isc.com (Brian R. Holt) (01/11/90)

In article <8106@portia.Stanford.EDU>, thewho@portia.Stanford.EDU (Derek
Fong) writes:
> Does anyone know what RAM Cache settings optimize the speed of the Mac.
> ....
> Has anyone out there tried the latest Virtual 2.0.  Is it reasonably fast?

A RAM cache will speed up your disk accesses, by caching them in main
memory. "Virtual" will give the appearance of more main memory by
swapping it out to disk.

Does it strike anyone else as amusing that someone might consider using
them both at the same time? (Hey, you know if you used Virtual 2.0, you
could make it look like you had 8 Meg of RAM, and then use 2 of those
megabytes as a RAM cache! :-).

		=brian

brian@ima.isc.com
US 617-661-7474 x206
near the Charles River

siegel@endor.harvard.edu (Rich Siegel) (01/14/90)

In article <15609@haddock.ima.isc.com> brian@ima.isc.com writes:
>In article <8106@portia.Stanford.EDU>, thewho@portia.Stanford.EDU (Derek
>Fong) writes:
>
>Does it strike anyone else as amusing that someone might consider using
>them both at the same time? (Hey, you know if you used Virtual 2.0, you
>could make it look like you had 8 Meg of RAM, and then use 2 of those
>megabytes as a RAM cache! :-).

	Actually, if your disk cache is sufficiently small, and the amount
of physical memory is sufficient large (I have 5MB), then you can actually
benefit from using the RAM cache with Virtual, because the disk cache hits
will be fairly frequent, while page swaps will be fairly infrequent.

R.


~~~~~~~~~~~~~~~
 Rich Siegel
 Staff Software Developer
 Symantec Corporation, Language Products Group
 Internet: siegel@endor.harvard.edu
 UUCP: ..harvard!endor!siegel

"When someone who makes four hundred and fifty dollars an hour wants to
tell you something for free, it's a good idea to listen."

~~~~~~~~~~~~~~~