How RAM Cache Works on a Macintosh
  
PSS ID Number: Q141953
Article last modified on 11-14-1997
 
6.x 7 7.01 7.10 7.5
 
MACINTOSH
 

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The information in this article applies to:
 
 - Apple Macintosh System Software versions 6.x, 7, 7.01 7.10, 7.5
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SUMMARY
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This article explains how disk cache (or RAM cache in System 6) works.
 
MORE INFORMATION
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Disk cache is a portion of memory reserved for frequently accessed
information that your Macintosh would ordinarily have to read from the hard 
disk. Disk caching allows your computer to access this information quickly 
from RAM.
 
Note that memory set aside for the disk cache will not be available for
other programs.
 
In System 7, the Disk Cache option is always on. You can set the cache size 
from 32K up to a megabyte (MB) or more with the Cache Size box in the
Memory control panel. Apple recommends a disk cache size of 128K-256K for
System 7. If you frequently access large files or programs from floppy disk 
a cache size of 348K may improve performance. Changes made in the Cache 
Size box will only take effect when you restart the Mac.
 
Accessing the Disk Cache Option
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If you are using System 7, use the following steps:
 
1. On the Apple menu, click Control Panels.
 
2. Select the Memory control panel.
 
If you are using System 6, double-click the General icon in control panel.
 
Determining the Size of Ram Cache
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If you are running MultiFinder, set 32K of cache for each MB of RAM
installed on your Macintosh. The maximum under MultiFinder is 348K for each 
megabyte installed on the Macintosh. Changes made to the cache size will 
only take effect when you restart the Macintosh.
 
If you are not running MultiFinder, the Cache size should equal
25 percent of your total RAM.
 
Additional query words: number mac multi finder ram cash 6.0   6.0.2
6.0.3  6.0.4 6.0.5
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Keywords          : kb3rdparty kbenv
Version           : 6.x 7 7.01 7.10 7.5
Platform          : MACINTOSH
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Copyright Microsoft Corporation 1997.