Re: Optimum GS/OS Ram Cache?

[a2pro.gelamp@genie.com]

TTSH35A@prodigy.com (Phil Abel) writes:

>I've been trying to figure out what an optimal size for the GS/OS disk 
>cache setting should be... Has anyone else done any experimenting with 
>this feature? Does a huge 1MB or so setting make any sense, or do you 
>just need a couple hundred k? I've been using the 256k-384k range, but 
>can't say I've noticed a lot of performance improvement over no cache at 
>all. I have an unaccelerated GS (though I hope this will change soon!) so 
>don't know if there is a more significant performance improvement from a 
>disk cache that is noticable on a faster machine. For disk access I use a 
>Vulcan Gold 40MB Internal as well as a SCSI chain (plain ol' Rev C Apple 
>SCSI card) connected to a CDSC, an SC40Tape, and a Fujitsu 410MB SCSI2 HD.
>. don't know if the cache makes any difference or not on SCSI devices 
>(or removable media devices, like my CD/Tape)? Think the majority of my 
>performance improvements need to be realized via a faster SCSI card and a 
>Zip Chip right now, but in the interest of "tweaking" the system, any 
>input regarding the GS/OS cache would be appreciated. Thanks.

the best size for the cache is probably no more than 256k or so.. I
personally use 128k.  why?  Well, normally GS/OS only caches directory
blocks.. those parts of the disk that list what files are on the disk.
You normally won't access a megabyte worth of directory blocks :)

Some programs will tell GS/OS to cache other files, but most don't, since
most GS applications load an entire file into memory when working with it
anyway. (so why cache it?  It would just take up twice as much memory.)
--
         Tim Buchheim           |  Apple II user and programmer
         ~~~~~~~~~~~~           |  Editor, GEnieLamp A2Pro
   tim.b@tiberius.st.hmc.edu    |  Asst. Sysop, A2Pro RT on GEnie
   tim.b@genie.com              |  
   a2pro.gelamp@genie.com       |  "Whatever" -- K.S.  :)