Help me understand this memory statistics from Process Explorer
I am trying to make a very rough measurement of the amount of memory that my big financial calculation requires to run. It is a very simple command line tool that prices a large number of financial instruments and then prints the result.
I decided to use Process Explorer to view the memory requirements of a program. Can anyone explain the difference between the two fields labeled as a and b in the screenshot:
I currently believe that:
The value denoted by "a" (peak private bytes) is the largest amount of memory (both actual physical memory and virtual memory on disk) that has been allocated to a process at any time.
The value labeled "b" (Peal Working Set) is the largest amount of physical memory allocated at any given time during the entire process.
source to share
From here :
Working set is a collection of memory pages that have recently been touched by the threads of a process. If the free memory on the computer exceeds the threshold, the pages remain in the working set of the process even when they are not in use. When free memory falls below the threshold, pages are clipped from working sets. If the pages are needed, they will be softly pushed back into the working set before leaving main memory.
[ Private Bytes ] are bytes allocated by this process that cannot be shared with other processes.
What "peak" means in this context should be obvious.
source to share
Random thoughts from observations and what the Process explorer demo says. The working set is in the Physical Memory section of the display, so anyone who says it is virtual memory is confused. And it changes to odd numbers as RAM usage usually changes, so it looks like a working set - it's physical memory. Private bytes, on the other hand, are listed as virtual memory. And, watching the change, it looks like it is a multiple of 16K, since virtual memory usually changes when it folds memory pages, not just random bits. For some reason I thought it should be 64k pages, but it depends on the machine and the Windows version I suppose.
source to share