Memory

The Memory window shows information about the windows memory. 

Memory (MegaBytes)

Available Amount of physical memory available to processes running on the computer. It is calculated by adding the amount of space on the Zeroed, Free, and Standby memory lists. Free memory is ready for use; Zeroed memory consists of pages of memory filled with zeros to prevent subsequent processes from seeing data used by a previous process; Standby memory is memory that has been removed from a process' working set (its physical memory) on route to disk, but is still available to be recalled.
Commited Amount of committed virtual memory. Committed memory is the physical memory which has space reserved on the disk paging file(s). There can be one or more paging files on each physical drive.

Pool Nonpaged (unit)

Allocs Number of calls to allocate space in the nonpaged pool. The nonpaged pool is an area of system memory area for objects that cannot be written to disk, and must remain in physical memory as long as they are allocated. It is measured in numbers of calls to allocate space, regardless of the amount of space allocated in each call.
KBytes Size of the nonpaged pool, an area of system memory (physical memory used by the operating system) for objects that cannot be written to disk, but must remain in physical memory as long as they are allocated.

Page Transaction/sec

Reads Rate at which the disk was read to resolve hard page faults. It shows the number of reads operations, without regard to the number of pages retrieved in each operation. Hard page faults occur when a process references a page in virtual memory that is not in working set or elsewhere in physical memory, and must be retrieved from disk. This counter is a primary indicator of the kinds of faults that cause system-wide delays. It includes read operations to satisfy faults in the file system cache (usually requested by applications) and in non-cached mapped memory files. Compare the value of "Pages Reads/sec" to the value of "Pages Input/sec" to determine the average number of pages read during each operation.
Writes Rate at which pages are written to disk to free up space in physical memory. Pages are written to disk only if they are changed while in physical memory, so they are likely to hold data, not code. This counter shows write operations, without regard to the number of pages written in each operation.

Pages/sec

Faults Average number of pages faulted per second. It is measured in number of pages faulted per second because only one page is faulted in each fault operation, hence this is also equal to the number of page fault operations. This counter includes both hard faults (those that require disk access) and soft faults (where the faulted page is found elsewhere in physical memory.) Most processors can handle large numbers of soft faults without significant consequence. However, hard faults, which require disk access, can cause significant delays.
Input Rate at which pages are read from disk to resolve hard page faults. Hard page faults occur when a process refers to a page in virtual memory that is not in its working set or elsewhere in physical memory, and must be retrieved from disk. When a page is faulted, the system tries to read multiple contiguous pages into memory to maximize the benefit of the read operation.
Output Rate at which pages are written to disk to free up space in physical memory. Pages are written back to disk only if they are changed in physical memory, so they are likely to hold data, not code. A high rate of pages output might indicate a memory shortage. Windows writes more pages back to disk to free up space when physical memory is in short supply.
Total Rate at which pages are read from or written to disk to resolve hard page faults. This counter is a primary indicator of the kinds of faults that cause system-wide delays. It is the sum of "Pages Input/sec" and "Pages Output/sec". It is counted in numbers of pages, so it can be compared to other counts of pages, such as "Page Faults/sec", without conversion. It includes pages retrieved to satisfy faults in the file system cache (usually requested by applications) non-cached mapped memory files.

Transition faults/sec

Faults Rate at which page faults are resolved by recovering pages that were being used by another process sharing the page, or were on the modified page list or the standby list, or were being written to disk at the time of the page fault. The pages were recovered without additional disk activity. Transition faults are counted in numbers of faults; because only one page is faulted in each operation, it is also equal to the number of pages faulted.

Cache (MegaBytes)

Cache is the sum of the following counters:
 
System Cache Resident Size of the pageable operating system code in the file system cache. This value includes only current physical pages and does not include any virtual memory pages not currently resident. It does equal the System Cache value shown in Task Manager. As a result, this value may be smaller than the actual amount of virtual memory in use by the file system cache.
System Driver Resident Size of the pageable physical memory being used by device drivers. It is the working set (physical memory area) of the drivers.
System Code Resident Size of the operating system code currently in physical memory that can be written to disk when not in use.
Pool Paged Resident Size of the paged pool. The paged pool is an area of system memory (physical memory used by the operating system) for objects that can be written to disk when they are not being used. Space used by the paged and nonpaged pools are taken from physical memory, so a pool that is too large denies memory space to processes.

See also:





Go back to the Learning center:


Copyright © AgileLoad. All rights reserved.
Agile Load testing tool| Contact AgileLoad | Terms of Use | Sitemap