Microsoft KB Archive/94265

= Windows NT and Real-Time Operating Systems =

PSS ID Number: 94265

Article Last Modified on 11/20/2003

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The information in this article applies to:


 * Microsoft Windows NT Server 3.1
 * Microsoft Windows NT Workstation 3.1
 * Microsoft Windows NT Advanced Server 3.1

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This article was previously published under Q94265



SUMMARY
You can use a variety of criteria to measure the performance of a real-time system. The following are examples of the kinds of measurements that might be used to determine real-time throughput:


 * Longest critical region that the kernel blocks task activation during a system call
 * Maximum time that interrupts are disabled
 * Context switch time (scheduler time to save/restore registers, etc.) for threads within the same process (no change in memory context) and for threads in different processes (save/restore memory context)
 * Interrupt response time (latency between the occurrence and execution of the first instruction)
 * Interrupt task response time (worst case task dispatch latency for task waiting on the interrupt)
 * Performance of interprocess communication facilities (semaphores, queues, pipes, etc.)

Because such specifics are hard to measure, this article provides a general discussion of the suitability of Windows NT as a real-time system.



MORE INFORMATION
Users often want a total program development/GUI user environment, virtual memory, and so forth, without any corresponding reduction in response time. Real-time systems, however, are dedicated systems for the duration of an &quot;event.&quot; During that time, the system is essentially locked, and no other activity can take place except that real-time event. (Note that very few situations demand microsecond or millisecond response time.)

Windows NT has the same basic structure as VMS. Windows NT has more efficient mechanisms than RSX-11M. It has a better design than VAXELN, which is a real-time embedded OS toolkit. All three of these systems are very successful.

Although Windows NT has good real-time capabilities; it is not designed to compete with a special purpose real-time system. If you need such a system, obtain the special real-time hardware and supporting operating system.

Additional query words: prodnt real time realtime winnt

Keywords: kbother KB94265

Technology: kbWinNT310Search kbWinNTAdvSerSearch kbWinNTAdvServ310 kbWinNTS310 kbWinNTS310search kbWinNTsearch kbWinNTSsearch kbWinNTW310 kbWinNTW310Search kbWinNTWsearch

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