What is my peak total memory usage? How much of my RAM is actually being actively used?

Is there an app or utility in Windows that shows me the peak value of in-use memory (i.e., the total of the shareable and private memory of processes, drivers and the operating system) (not standby nor free)?

I've got lots of memory and I'm installing an in-memory file cache, called "eBoostr", and would like an idea how much memory to allocate for it and still avoid deteriorating page faults.

Essentially, I want the answer to the question, "How much of my RAM is actually being actively used?"

memory-management

William C

Posted 2010-11-20T07:34:22.793

Reputation: 31

Answers

Sysinternals Proccess Explorer will give you a huge amount of control and data about your system.

link text

Allan

Posted 2010-11-20T07:34:22.793

Reputation: 131

Okay, Allan, where exactly in Process Explorer can I see the peak value of total in-use memory? "View > System Information" shows it in the last five minutes, but I need the peak value across a longer period. – William C – 2010-11-20T09:01:53.080

Click on the one of the graphs to open the system information dialogue. On the memory page (if you are running the latest--this dialogue has just had a major update) look at the peak commit (maximum amount of allocated memory: physical and paged) since the last boot. – Richard – 2010-11-20T10:04:57.287

The technical answer is, "all of it," no matter what your size. Memory that isn't being used for applications is used as the file and block cache for your filesystem. You really do want some of this memory for caches as it can improve how applications behave since it can cache key app files instead of reading directly from disk each time. How much you need for this depends on your applications and usage patterns.

Looking at eBoostr, it directly addresses this very use-case, so you can probably pare your OS caches down a lot farther than you otherwise could get away with. That said, in-RAM cache will still outperform eBoostr, but eBoostr will out perform reading directly from disk (assuming USB). If they're doing it in RAM as well, it sounds like they're just pre-caching files in RAM so the OS doesn't have to do it.

SysAdmin1138

Posted 2010-11-20T07:34:22.793

Reputation: 5 239

Yes, eBoostr is also doing it in RAM -- exactly like those startup application preloaders of ye-old MS Office 2003 and of the newer Adobe Acrobat. eBoostr pre-loads one huge file at startup and uses its contents as a file cache replacement. – William C – 2010-11-20T09:11:45.617

Exact details will depend on your Windows version, but Performance Monitor is the tool integrated in modern Windows systems to monitor such things.

Jason Sherman

Posted 2010-11-20T07:34:22.793

Reputation: 1 071