The Task Manager utility is excellent for getting a
quick overview of the current state of the system. To get it on-screen,
press Ctrl+Alt+Delete. If the Windows Security dialog box appears, click
the Task Manager button.
Tip
To bypass the Windows Security dialog box, right-click an empty section of the taskbar and then click Task Manager.
The Processes tab, shown in Figure 1,
displays a list of the programs, services, and system components that
are currently running on your system. The processes are displayed in the
order in which they were started, but you can change the order by
clicking the column headings. (To return to the original, chronological
order. you must shut down and restart Task Manager.)
In addition to the name of each process and the user who started the process, you also see two performance measures:
| CPU | The
values in this column tell you the percentage of CPU resources that
each process is using. If your system seems sluggish, look for a process
that is consuming all or nearly all of the CPU’s resources. Most
programs will monopolize the CPU occasionally for short periods, but a
program that is stuck at 100 (percent) for a long time most likely has
some kind of problem. In that case, try shutting down the program. If
that doesn’t work, click the program’s process and then click End
Process. Click Yes when Windows XP asks whether you’re sure that you
want to do this. |
| Mem Usage | This
value tells you approximately how much memory the process is using.
This value is less useful because a process might genuinely require a
lot of memory to operate. However, if this value is steadily increasing
for a process that you’re not using, it could indicate a problem and you
should shut down the process. |
Tip
The four default columns
in the Processes tab aren’t the only data available to you. Select the
View, Select Columns command to see a list of more than two dozen items
that you can add to the Processes tab.
The Performance Tab, shown in Figure 2, offers a more substantial collection of performance data, particularly for that all-important component, your system’s memory.
The graphs show you both the current value and the values over time for the CPU usage (the total percentage of CPU resources that your running processes are using) and the Page File Usage.
What is a page file?
Your computer can address memory beyond what is physically installed on
the system. This nonphysical memory is called virtual memory,
and it’s implemented by using a piece of your hard disk that’s set up
to emulate physical memory. This hard disk storage is actually a single
file called a page file (or sometimes a paging file or a swap file).
When physical memory is full, Windows XP makes room for new data by
taking some data that’s currently in memory and swapping it out to the
page file. The PF Usage graph shows the current size of the page file,
and the Page File Usage History graphs shows the relative size of the
page file over time.
Below the graphs are
various numbers. The items in the Totals group appeal only to
programmers, so we’ll skip them. Here’s what the other values mean:
Note
The memory values are listed in kilobytes. To convert to megabytes, divide by 1,024.
| Physical Memory Total | The total amount of physical RAM in your system. |
| Physical Memory Available | The
amount of physical RAM that Windows XP has available for your programs.
Note that Windows XP does not include the system cache (see the next
item) in this total. |
| Physical Memory System Cache | The amount of physical RAM that Windows XP has set aside to store recently used programs and documents. |
| Commit Charge Total | The combined total of physical RAM and virtual memory the system is using. |
| Commit Charge Limit | The combined total of physical RAM and virtual memory available to the system. |
| Commit Charge Peak | The maximum combined total of physical RAM and virtual memory the system has used so far in this session. |
| Kernel Memory Total | The total amount of RAM used by the Windows XP system components and device drivers. |
| Kernel Memory Paged | The amount of kernel memory that is mapped to pages in virtual memory. |
| Kernel Memory Nonpaged | The amount of kernel memory that cannot be mapped to pages in virtual memory. |
Here are some notes related to these values that will help you monitor memory-related performance issues:
If
the Physical Memory Available value approaches zero, it means your
system is starved for memory. You might have too many programs running
or a large program is using lots of memory.
If
the Physical Memory System Cache value is much less than half the
Physical Memory Total value, it means your system isn’t operating as
efficiently as it could because Windows XP can’t store enough recently
used data in memory. Because Windows XP gives up some of the system
cache when it needs RAM, close down programs you don’t need.
If
the Commit Charge Total value remains higher than the Physical Memory
Total value, it means Windows XP is doing a lot of work swapping data to
and from the page file, which greatly slows performance.
If
the Commit Charge Peak value is higher than the Physical Memory Total
value, it means at some point in the current session Windows XP had to
use the page file. If the Commit Charge Total value is currently less
than Physical Memory Total value, the peak value might have been a
temporary event, but you should monitor the peak over time, just to make
sure.
In all of these situations,
the quickest solution is to reduce the system’s memory footprint either
by closing documents or by closing applications. For the latter, use the
Processes tab to determine which applications are using the most memory
and then shut down the ones you can live without for now. The better,
but more expensive, solution is to add more physical RAM to your system.
This decreases the likelihood that Windows XP will need to use the
paging file, and it also enables Windows XP to increase the size of the
system cache, which greatly improves performance.
Tip
If you’re not sure which
process corresponds to which program, display the Applications tab,
right-click a program, and then click Go to Process. Task Manager
displays the Processes tab and selects the process that corresponds to
the program.
