• Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint
Share this Page URL
Help

Chapter 9. Performance Tuning: Optimizin... > Windows 98 and Memory: A Primer

Windows 98 and Memory: A Primer

Entire books can be (and, indeed, have been) written about the relationship between Windows and memory. What it all boils down to, though, is quite simple: The more memory you have, the happier Windows (and most of your programs) will be. However, not everyone can afford to throw 64 megabytes of memory at their problems. We have to make do with less, and that, in essence, is what this chapter is all about. Later, I'll show you some ways to fight back if a lack of memory is slowing Windows 98 to a crawl.

The Move to 32 Bits

Windows 98 simplifies things (relatively speaking) by moving from the 16-bit segmented memory addressing that shackled DOS for so many years to the full 32-bit addressing associated with 80386 and higher processors. 32 bits can be arranged in 232, or 4,294,967,296, different ways, which gives programs an address space of 4GB. Not only that, but the 80386 and higher processors handle data in 32-bit pieces. This means that programmers no longer have the 64KB segment restrictions. Instead, they're free to reference any memory location in the full 4GB address space directly (with certain restrictions, as you'll see later). This is called a flat memory space. (Technically, they still use the segment/offset model; however, the segment register always points to the beginning of the address space.) Data is also no longer restricted to 64KB, but can be as large as 4GB. This new memory model is called a flat memory model, or sometimes a linear addressing model.


PREVIEW

                                                                          

Not a subscriber?

Start A Free Trial


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