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Re: real verses Virtual memory
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Re: real verses Virtual memory



On Sat, Oct 10, 2009 at 10:48 AM, jon <email@hidden> wrote:

> I could use an explanation then,   if you go into "activity monitor"   you
> will see a heading of "real memory"  and "virtual memory".....  specifically
> for all the current "Processes"..
>
> what does Apple mean by "real memory"?    in that,  I might see why you
> asked the question?    and why you think that i am using it incorrectly for
> my particular "process"...  i can see Apple label my process ashas bee using
> "real memory"?  and "virtual memory"  what does apple mean?


http://support.apple.com/kb/HT1342
http://support.apple.com/kb/TA20517

In a nutshell..

Real Memory is essentially how much physical RAM is currently being used by
the process. It doesn't count swapped out pages.

Virtual Memory is how much of the processes virtual memory space has been
"consumed" by allocations. Note just because an allocation was made in the
virtual memory space doesn't mean that any physical RAM or on disk swap has
been yet used. In fact pages related to the allocation may never be touched
by the process, hence never cause a page fault requiring the mapping of
physical/disk page.

-Shawn
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References: 
 >real verses Virtual memory (From: jon <email@hidden>)
 >Re: real verses Virtual memory (From: Michael Dautermann <email@hidden>)
 >Re: real verses Virtual memory (From: jon <email@hidden>)
 >Re: real verses Virtual memory (From: Jean-Daniel Dupas <email@hidden>)
 >Re: real verses Virtual memory (From: jon <email@hidden>)



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