the error does not handle it, the operating system performs a default action, typically involving the termination of the running process that caused the error condition, and notifying the user that the program has malfunctioned. Windows often reports such crashes without going to any details. An experienced user can retrieve detailed information using WinDbg and the minidump that Windows creates during the crash. UNIX-like operating systems report these conditions with such error messages as "segmentation violation" or "bus error", and may produce a core dump. Performance impact Page faults degrade system performance and can cause thrashing. Major page faults on conventional computers using hard disk drives can have a significant impact on their performance, as an average hard disk drive has an average rotational latency of 3 ms, a seek time of 5 ms, and a transfer time of 0.05 ms/page. Therefore, the total time for paging is near 8 ms (= 8,000 μs). If the memory access time is 0.2 μs, then the page fault would make the operation about 40,000 times slower. Performance optimization of programs or operating systems often involves reducing the number of page faults. Two primary focuses of the optimization are reducing overall memory usage and improving memory locality. To reduce the page faults, developers must use an appropriate page replacement algorithm that maximizes the page hits. Many have been proposed, such as implementing heuristic algorithms to reduce the incidence of page faults. A larger physical memory also reduces page faults. See also Bélády's anomaly Notes References John L. Hennessy, David A. Patterson, Computer Architecture, A Quantitative Approach () Tanenbaum, Andrew S. Operating Systems: Design and Implementation (Second Edition). New Jersey: Prentice-Hall 1997. Intel Architecture Software Developer's Manual–Volume 3: System Programming External links "So What Is A Page Fault?" from OSR Online (a Windows-specific explanation) "Virtual Memory Details" from the Red Hat website. "UnhandledExceptionFilter (Windows)" from MSDN Online. "Page fault overhead" for information about how page faults can crucially affect processing time. Virtual memory Memory management Computer errors