• Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint

Chapter 4. Memory

Mike Breeden is the chapter editor and author.

This chapter covers the types of memory in your Macintosh. The primary focus is on practical, useful information rather than technical details. I examine each of the memory types: DRAM (Dynamic Random Access Memory), cache, virtual memory, and special cases such as NVRAM (Non-Volatile RAM) and ROM (read-only memory). I also include links to memory-related guides and other resources on the Web. The goal is to give you the information you need to get the most out of the memory you have and to be able to add more RAM to your Mac. When I refer to main memory, I'm talking about DRAM (the RAM memory modules installed in your Mac).

RAM is one of the primary factors affecting system performance, and it's usually the first thing you upgrade unless your Mac shipped with a large amount of it. Regardless of your CPU (central processing unit) speed, too little RAM suffocates your machine's performance. Adding RAM is probably the most universally beneficial upgrade for your Mac, as it is a core component used by every application. If you run more than one program simultaneously, adequate RAM also reduces crashes and lockups.

If you own a PowerPC G3 or G4 Mac, there's never been a better time to buy memory. I recently bought a 256 MB DIMM (memory module) for less than I paid for a 16 MB module for my Power Mac 8500 three years ago.

In This Chapter

The Types of Memory

DRAM (Dynamic Random Access Memory)

Cache Memory

Virtual Memory

Video RAM



The RAM Disk

RAM Memory Types


Mac Models and Compatible SDRAM Types


Pre-PowerPC G3 Mac Memory Tips

Memory Interleaving

RAM Tips for CPU Upgrades

2K Refresh and 4K Refresh Memory

Apple's RAM Installation Guides

Memory-Buying Tips

Precautions for Handling Memory

  • Creative Edge
  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint