TOPIC This article explains why virtual memory should be turned on with Power Macintosh computers. DISCUSSION Application programs written for Power Macintosh computers have code stored in their data fork as one large code fragment, which is loaded into memory when you open the program. For this reason these kinds of applications require larger amounts of memory (RAM) when virtual memory is turned off. When virtual memory is turned on, they require much less RAM. Virtual memory on the Power Macintosh uses file-mapped virtual memory. This allows the code fragment to be divided up into 4K blocks and to only load when it is executing. If the program branches to code that is not in RAM, it is simply read in from the disk instead of all at once when the program is open. For maximum memory use, you should turn on virtual memory in the Memory control panel. Note: There are situations when turning virtual memory on may prevent optimal performance, such as playing a movie from a DVD-Video disc, for example. Turn virtual memory off if you suspect that it may cause issues with certain programs. Be sure to read the system requirements for your application programs. Generally, they say if virtual memory should be on or off. |
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| Document Information | |
| Product Area: | Computers |
| Category: | Power Macintosh |
| Sub Category: | General Topics |
| Keywords: | kppc, ksts |
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