The minimum requirement to run System 7 is a 2MB system with a hard disk.
User testing shows that this configuration is functionally equivalent to a
1MB configuration running system 6.0.7. But to take full advantage of
System 7 and multiple and/or larger applications you will need at least 4MB
of RAM.
Here is a rough guide to memory usage:
* 1MB - Use system 6 with one application.
* 2MB - Use System 7, the Finder, and one application.
* 2.5MB - Use System 7, the Finder, and one or two applications.
* 3MB to 5MB - Use System 7, the Finder, and multiple applications or one
large application.
* 5MB to 8MB - Use System 7, the Finder, and multiple large applications
and/or documents.
Because of System 7's built-in multitasking, users may launch a second
application without quitting from the first. In a 2MB system, this will
frequently produce an "Out of Memory" error message. To avoid these
messages, users with 2MB Macintosh computers should quit each application
before using another. This will not affect their ability to use the
multitasking features of System 7, such as background printing and file
copying.
System 7 consumes 500K to 1MB more memory than system software 6.0.x.
Consider adding one to two megabytes of memory to a Macintosh with limited
memory. Or use System 7's virtual memory feature, which is available on
the Macintosh SE/30, IIx, IIcx, IIci, IIfx, and Macintosh II with optional
PMMU.
Because of differences in system ROMs and video architecture, each
Macintosh configuration has slightly different system memory usage under
System 7. Here are the basic memory profiles of System 7 on various
Macintosh computers, using basic install with file sharing and program
linking turned off:
Memory Memory
System Consumed Free*
------------------ -------- ------
Macintosh Plus 1056K 992K
Macintosh SE 1125K 923K
Macintosh SE/30 1271K 777K
Macintosh Portable 1085K 963K
Macintosh Classic 1123K 925K
Macintosh LC 1298K 750K
Macintosh IIsi 1216K** 1085K***
Macintosh II 1275K 773K
Macintosh IIx 1268K 780K
Macintosh IIcx 1298K** 750K
Macintosh IIci 1202K 796K
Macintosh IIfx 1185K 2911K****
* Available application memory in a 2MB configuration. Any memory
above 2MB is available for application use as well.
** 8-bit color video consumes an additional 280K.
*** 3MB configuration
**** 4MB configuration
Note: Macintosh file sharing consumes an additional 260K.