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Win7-64 w 12GB won't use more than 4GB

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2ms

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Jul 17, 2006
I have a new Xeon Nehalem workstation with 12GB RAM running Windows 7 64-bit Enterprise edition.

No matter how many applications I open, at least according to Task Manager, the machine doesn't seem to ever use more than about 4GB ram. This doesn't make sense because I'm literally opening every application I've got including huge CAD assemblies in Pro/E, Adobe Creative Suite, 4 different browsers, Office, Visual Studio, Matlab, etc.

I never use all these apps at once. The point was to test whether or not my system has some kind of artificial limit set to where it won't use nearly all the RAM it's got. I decided to do this b/c was shocked to look at Task Manager and see only like 3.5GB being used while I had my largest CAD assembly open. So I decided to see what it would take to use up 10GB or something. But it seems like no matter what I do I can never get it to use more than about 4.

Is there some configuration setting I might need to change in order for Windows to take advantage of the full 12GB?
 
Fire up Orthos or Prime 95 and do a custom test with 12gb in ram testing.

I started up Prime 95 for 64-bit Windows with Custom set to 8 threads and 16000MB memory. But when I run it only 3.25GB is showing up as used by task manager.

What am I doing wrong?
 
Whats the total physical memory available in the task manager under the performance tab?

12285 (MB)

By the way, I was wondering, what's the difference between "Available" and "Free"? My available at this moment happens to be 10364 and my free at moment appears to be 1629. When I have a large CAD assembly open though my free will only be like 40 or something.
 
right click my computer and go to properties, does it show 12G there or 4G?

does it confirm and say x64 or x32

what if you take some sticks out, say 8G or 6G does it show?
 
If I recall my older Intel P965 P5BDeluxe had a seting in the bios that you needed to change in order to activate or use more than the 32bit limit of 3.XXGB

Specs list please.
 
Some older programs will be hard coded to only show >4gigs.

If your kernel *Windows* shows the proper amount. Then it is application specific.


The bottom line. If your OS shows you the right amount. .. You are good to go. If the application or program is mis-displaying the correct amount. It is a specific vendor issue. Your operating system is just very complex software.
As others mentioned. It could be a setting in your motherboard. But the Windows Kernel should be able to pick up the total amount of RAM installed. Per the physical kernel limits.

Sometimes, we have to rule out which product is giving issue. Start at hardware and work your way up from low level to software. The kerenl may of compiled during install as 32bit... Unlikely. Since it would show 32bit extensions.. None of the dual Program Files we expect on a 64bit Windows install. [ C:\Program Files & C:\Program Files (x86) ]
 
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By the way, I was wondering, what's the difference between "Available" and "Free"? My available at this moment happens to be 10364 and my free at moment appears to be 1629. When I have a large CAD assembly open though my free will only be like 40 or something.

Since Windows 7 manages memory by itself, I am pretty sure that available memory is the memory that is currently being used by Windows; but it makes room whenever you need to use more memory. That is why your theme will turn into windows basic when you use more memory. Free means that nothing is using that amount of memory.

EDIT: Enabling page filing on Windows 7 is a good idea. It enabled me to use more than 75% of my physical memory.
 
i think we need confirmation that the bios is seeing all 16gb first, and then windows is in fact 64bit and seeing all 16gb as well. next time you boot up, get in to the bios config (usually by hitting delete, or escape). usually will be right there on the first screen. then follow the other posts above to confirm all the windows stuff
 
The performance tab in his task manager shows 12GB (#5). That means that Windows has found all 12 GB and is able to use them.
 
Turn off your page file and try the same thing and see if it uses more or just gives you an out of memory error. If it does use it all, then it's just windows trying to stay under 40% of it's available. If not then you have a problem elsewhere :/
 
I hate to say it but your problem is not actually a problem at all. Windows 7 is absolutely amazing with ram management. you have 12gb and its way overkill for what you are doing.
 
All OS's manage memory by themselves?

They do, but Windows 7 manages memory unlike any other OS ( <- That should of been my opening sentence for that post). For example, in Win Xp the memory it uses is almost static, and you can turn off page filing. Win 7 changes its operating memory whenever it feels like; and if you turn off page filing Win 7, it will close our programs at about 75%.
 
^^ i recall hearing that even if you turned off page file in XP, it wasnt actually off... it still had some..
But i do agree, since Vista, windows memory management has taken a great turn for the better with superfetch and such.

I hate to say it but your problem is not actually a problem at all. Windows 7 is absolutely amazing with ram management. you have 12gb and its way overkill for what you are doing.

Irrelevant... there is a problem, somewhere, possibly windows 7 or hardware.

If he installed 12g windows 7 x64 should show 12G, none of us are to claim that 12g is over kill for him, one day they may decide to start 3 or 4 VM's for the fun of it for some testing or something else, or get into photo editing...

i thought 6G would be enough for my work rig, but just yesterday i found myself go to 6.3G of ram usage, since i am testing out MySQL clustering on windows with in Vm's.
 
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