19-7LESSON 1 USING TASK MANAGERF19US03FIGURE 19-3 THE PERFORMANCE TAB...
19
-
7Lesson 1
Using Task Manager
F19us03
Figure 19-3 The Performance tab provides real-time performance data about the CPU, RAM, and virtual memory.Table 19-2 describes the fields that are displayed by default on the Performance tab inTask Manager.Table 19-2 Performance Tab FieldsField DescriptionCPU Usage The percentage of time that the processor is busy. If this graph displays a high percentage continuously (and not when there is an obvious reason, such as a big application), your processor might be overloaded. If your computer has two processors, two graphs are shown. If this value runs continuously over 80 percent, you probably see a noticeable improve-ment in performance if you upgrade your processor.CPU Usage History The percentage of time that the processor is running a thread other than the idle thread shown over time. You can use the Update Speed com-mand on the View menu to specify how often the values are refreshed. The High value updates about twice per second; Normal value updates once every two seconds; Low value updates once every four seconds. You can also pause the updates and update the view manually by press-ing F5. This is a useful method if you want to monitor some specific activity. Note that Task Manager itself uses processor time. The more fre-quently you update the display, the more processor time it uses, which throws off the accuracy of whatever you are analyzing.PF Usage The amount of virtual memory used (in MB). Page File Usage The amount of virtual memory used, shown over time. Values set using Historythe Update Speed command affect this history as well.Total: Handles The number of object handles in the tables of all processes. A handle represents a specific input/output (I/O) instance of a thread. Threads The number of running threads, including one idle thread per processor. A thread is an object within a process that runs program instructions.Processes The number of active processes, including the idle process. A process can have multiple threads, each of which in turn can have multiple han-dles.The amount of physical RAM installed in the computer.Physical Memory (K): TotalAvailable The amount of physical memory available to processes. System Cache The amount of physical memory released to the file cache on demand.Commit Charge: The size of virtual memory in use by all processes.Total Limit The amount of virtual memory that can be committed to all processes without enlarging the paging file. Peak The maximum amount of virtual memory used in the session.Paged The size of the paged pool allocated to the operating system. The paged pool is data in physical memory that can be written to the page file if Windows needs to make space in physical memory for other data.Nonpaged The size of the nonpaged pool allocated to the operating system. Win-dows cannot page all memory to a page file. In particular, many threads created by the Windows kernel cannot be paged.The sum of the paged and nonpaged memory.Kernel Memory (K): Note When Task Manager is running, Windows XP Professional displays an accurate minia-ture CPU usage icon on the taskbar. If you point to the icon, Task Manager displays the per-centage of processor usage in text format.