Back when memory cost $50 per megabyte, we advised people to install as much memory as they could afford. With memory now selling for pennies per megabyte, we advise people to install as much memory as their motherboards will accept.
How much memory you actually need depends on the operating system and applications you use, how many windows you keep open, which background services and processes you run, and so on. Memory is more important than processor speed when it comes to system performance. Windows XP runs faster on a slow Celeron with 256 MB than on a fast Pentium 4 with 64 MB.
Using a big swap/paging file cannot substitute for having enough RAM. Windows virtual memory allows you to run more and larger programs than fit into physical memory by temporarily swapping data from RAM to a disk file. When Windows swaps to disk, performance takes a major hit. If your hard disk clatters away every time you switch between running applications, that's a sure sign that heavy paging is going on and that your system needs more memory. RAM is cheap. Install enough of it to minimize use of the paging file.
To determine how much memory you need, choose the following category that best describes your usage pattern. If you fall between two, choose the higher. Note that newer versions of applications usually require more memory.
Web browsing, email, casual word processing and spreadsheets, checkbook management, and simple games; one or two windows open; particularly if using software one or two versions behind current releases.
Applications listed previously, particularly current versions; three to five windows open; using more demanding applications, including casual database updates and queries, complex spreadsheets, light/moderate programming, and mainstream games. File and print sharing in small workgroups or home networks.
Memory-intensive applications?e.g., Photoshop; speech/pattern-recognition software; many windows open; multiple background services; graphics-intensive games such as Quake III; heavy programming, especially with an Integrated Development Environment (IDE) and doing frequent compiles and links. File and print sharing for large workgroups or departmental groups. Limited use as an application or database server.
Professional scientific, engineering, and statistical applications; manipulating very large data sets. Use as a consolidated file, print, application, and database server.
Table 5-1 lists the minimum amount of memory we recommend by operating system and usage. These are ad hoc rules based on our experience, so your mileage may vary. More is always better because using more than the recommended minimum contributes to system stability. Windows 9X is of questionable robustness for Heavy usage, let alone Extreme usage, so we do not provide recommendations for Windows 9X in Extreme usage.
|
Operating system |
Light |
Typical |
Heavy |
Extreme |
---|---|---|---|---|
Windows 95 |
24 MB |
64 MB |
128 MB |
N/R |
Windows 98/98SE |
32 MB |
64 MB |
128 MB |
N/R |
Windows Me |
64 MB |
64 MB |
128 MB |
N/R |
Windows NT 4 Workstation |
64 MB |
128 MB |
256 MB |
384+ MB |
Windows NT 4 Server |
96 MB |
256 MB |
512 MB |
768+ MB |
Windows 2000 Professional |
128 MB |
256 MB |
512 MB |
1024+ MB |
Windows 2000 Server |
128 MB |
256 MB |
512 MB |
1024+ MB |
Windows XP Home/Professional |
128 MB |
256 MB |
512 MB |
1024+ MB |
Linux (GUI workstation) |
128 MB |
256 MB |
512 MB |
1024+ MB |
Linux (text-based server) |
128 MB |
256 MB |
512 MB |
1024+ MB |
Each operating system has a "sweet spot," which depends on the application mix, but is typically about midway between our recommendations for Typical and Heavy usage. Adding memory increases performance until you reach the sweet spot, but adding more than that results in decreasing returns. We generally find the sweet spot for Windows 95/98/Me to be 96 MB; for Windows NT Workstation 4.0, 192 MB; and for the remaining operating systems, 384 MB. Your mileage may vary.
In general, the best way to determine if you've reached the sweet spot for your own mix of applications and your personal working style is to keep an eye on how frequently the system pages out to the hard disk. If that happens frequently, you need more memory. If your system pages only occasionally, you probably have enough memory. Our rule is simple. If in doubt, always err on the side of having more memory rather than less.
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