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scott967

Good Reading On Virtual Memory

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OK, now I'm dizzy! Keep in mind that the "Virtual Memory" causing our OOMs is NoT Pagefile. "Windows assigning the file cache a certain amount of virtual memory does not dictate how much file data it actually caches in physical memory; it can be any amount from none to more than the amount that's addressable via virtual memory."If you can untangle that quote, that's what the author is trying to say (anyone read the philosopher George Berkeley?). BTW, the author may know his stuff, but his communication skills are rough. If it seems confusing, it's Not just you're inability to "get it."

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He's probably better at communicating in C than English :(The way I understand memory addressing...Without the /3gb switch, 32-bit apps running on top of 32-bit Windows can address 2GB max..then you run out of memory whether you have 512MB or 8GB of actual RAM installedWith the 3GB switch, large address aware 32-bit apps on a 32-bit Windows get to use 3GB, but this can potentially cause stability issues64-bit XP and Vista gives large address aware apps access to 4GB of memory (actual RAM or virtual memory), other 32-bit apps only get 2GB of address spaceFSX.exe seems to be large address aware meaning it should be able to address 4GB of memory on a 64-bit system.

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That's the way I 'get it' too. It was especially interesting to see the term "Virtual Memory" applied to Virtually Everything that wasn't a physical ram stick. No wonder we poor lay folks can't keep it straight. However we did get a lock-down that the virtual memory function called Address Space can be measured by Process Explorer's column called "Virtual Size." This describes the 2-3-4G limits that will OOM a program regardless of physical ram installed. It was also interesting to be introduced to the concept of "Commit" and "Commit limit." It appears that busting the Commit Limit can cause a shut down too. On my 64bit op system, I ran a flight. "Commit" was nowhere near the "Commit Limit." Thank goodness we don't have to worry about that too! Fun stuff.

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