Are there any downfalls to allocating the maximum amount of virtual memory?  Is there any reason why I should not? 

I found out that my laptop might be able to run FS better than my desktop if I can max out the virtual memory.

Virtual Memory is just space on your hard drive reserved for or containing program data which is used instead of RAM.

Either the programmer wishes to free system ram by using virtual memory (page file) or the program simply stores too much data to fit comfortably in RAM.

The program's access time for data stored on the hard disk is very slow compared to data held in memory, So critical functions are carried out in RAM while non time critical functions can be written to and accessed from the page file.

I think that's kinda how it works....

I think maxing out the page file (virtual memory) is not what you would call it. You simply need a page file reserve on your HDD large enough to hold all the paged data in a multi tasking environment.

You can also set the minimum and maximum size the same, say, 1.5 gb, that way, windows doesn't try to constantly alter the size of virtual memory as it does under windows management. I've never actually measured the benefit of this tweak.

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Why would think that? Virtual Memory is Vitual Memory, ie...... Page File. Allocating shared system RAM for an onboard video processor has nothing to do with virtual memory.

Windows automatically controls the "Virtual Memory" size, it constantly re-sizes the page file to what ever size it's contents are if you have the default setting of "System Managed"
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It doesn't work like that, it works as I explained above.

The only way to double your RAM is to add RAM modules to your mainboard. You can however, double your Virtual RAM, or Virtual Memory, or delete it all for that matter, (not recommended). Just remember that Virtual Memory is not virtual at all, it is real data taking up space on your hard disk.




 

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That is ok for systems with 512MB or less.  Once above that you need to use 2.5GB minus system RAM, or 2GB minus system RAM, depending on preference.

Well if youve got a raptor or a SATA drive it wouln't make that much difference.

Cheers
Cameron

Exactly, if you want to spend the money, a nice SATA/RAID solution helps a LOT by offering greater bandwidth for disk I/O. In addition, you could put the swapfile (pagefile) on a dedicated partition. A word of caution though, WinX platform doesn't always work as advertised when you "move" the Swapfile (Virt mem file).  This is especially true with XPSP2 and above.

BTW.. I find the forums here awesome! It's a pleasure to find so many so many folks that know what's going on and are willing to help!

You tell 'em Nick!

So, how well does windows manage the page file, and is there truly a benefit in setting a fixed page file size, has anyone measured or documented it?

I will answer and then drop this subject:


1.
It is very much possible to run XP and most programs with 2GB RAM and very little pagefile.  Some programs require a pagefile and won't work without it.

A:
I never said it was not possible… what I indicated is that it is not advised to do that because of those programs that need chunks of page file available to them. To give someone advice without knowing EXACTLY what is on their system and how they use their system is like doctor prescribing a medication and treatment without an examination, lab tests and observations, therefore it is best to NOT suggest something that can and WILL crash someone’s computer and to stick with what will not cause crashes, poor performance or other intermittent problems.



2.
To get absolute max performance and to stop XP using the hdd for memory you must turn pagefile off.  This elimates all jerkiness and loading lag.  XP will try and use only the system RAM and will be much quicker.  However because XP can't function very well without atleast a small amout of pagefile it is recommended that 200MB is set aside.

A:
Wrong… if you wish to run without the page file, the minimum to set aside is based on how much information you need in your memory dump for diagnostics. (System properties, Advanced, Startup and Recovery) for a minimal memory dump a 2mb page file is required. The page file space is needed for memory dumps based on your individual needs. a “minimal memory dump requires 2mb of page file space. If you want a kernel memory dump, a page file the size of the PM is needed, a full memory dump, PM x 1.5 page file is recommended. That is where Microsoft gets the PMx1.5 recommend page file size from.. but that is NOT set in stone, only a starting point

Next, please post the MSKB that states that a zero page file should be used for games or to increase windows performance. In fact MSKB’s say the opposite.



3.
XP uses 1.5xRAM to calculate its pagefile, this was based on an average system for the time which was about 256MB-512MB RAM.    

A:
Wrong… Microsoft set that because it is impossible for Microsoft Windows to analyze a system and determine the correct page file size for an individual use so it is based on a full memory dump for diagnostics and not based on “the good-old-days”



4.
2-3xRAM is not a very precise figure to use.  What about systems that have 128MB, giving 256MB-384MB virtual memory, that is not enough for that system.  Why does a system with more RAM need more pagefile?  A system with 2GB RAM would need 4GB-6GB pagefile!!!  That is way too much!  Any figure between 200MB and 500MB would be more than enough for that system and todays games.  

A:
You are again assuming everyone who asks the page file question is doing nothing but gaming. Also my recommendation covers everyone. Assuming someone runs 256mb PM and they use the 2-3x method, a static 500mb to 768mb page file covers them. Why? Because anyone running Windows and games or video content with only 256mb of PM will never see any performance gain from more than 500-768 static page file size… on the other hand they WILL most likely crash and burn on a zero or 200mb page file. If Windows needs more pagefile, it will let the user know in a message box. At that point they can increase the size again. http://support.microsoft.com/kb/315270/en-us

BTW.. I serously doubt anyone is booting WindowsXP and running FS9 or 128mb of memory.. even 256mb is silly to use with FS9, but anything is possible.


5.
Not too many people that have typical systems (for games etc...) do graphics editing too.  Most have a separate system for that stuff and that requires a different set-up like you said.  

A:
And that is why I do not recommend silly, internet fantasy, page file settings… because I do not know what the person uses their system for and I do not assume it either.



6.
Memory dumps are stored in C:\WINDOWS\Minidump not pagefile.

A:
Yes, it is written to the hard drive but that is why the settings for the page file are recommended in item #2 above, you said it yourself… you need the space for the memory dump which goes to the page file FIRST before it is written to the hard drive in “minidump” or the system will crash again when trying to write the minidump file.

If you wish to get right down to the hard line technical aspects of how to set a gauge pagefile size, it is done by using the performance counters and monitoring the memory I/O of a system… YES, you can run a small page file: IF you know for a FACT system does not need it. A  large page file (which is based on 2-3x PM) does NOT make Windows doggy or slow it down, that is a an internet MYTH, all it does is take up space However it ALSO functions as a prefetch and stores memory items from the PM which have not been paged in a period of time, therefore it does help performance by having those memory blocks ready for direct reload without looking all over the HDD for the separate chunks. That INCLUDES 3D Games (see next post)