Windows – 12GB of RAM only 8GB is usable on Windows 7 64-bit

64-bitmemorywindows 7

I'm running a Dell Studio XPS, with quad core processor, two threads per core, with 12GB of installed RAM. According to Windows, only 7.99GB of that RAM is usable.

The really weird part is, up until two weeks ago I only had 8GB of RAM and then only 3.99GB was usable. So 4GB of RAM is consistently being taken.

I've checked in every screen, under every option in my BIOS and there doesn't seem to be a memory option there at all (that's a damn Dell for you). I've read that a lot of times this can occur because of the video card stealing some RAM for itself.

Is there some way I can check this, other than the BIOS? I have onboard graphics, not a separate card.

I'm running Windows 7 64-bit.

Best Answer

Alright so I'm not sure why in the hell this did the trick. But this computer I'm using has had many previous users, so I had like 9 jdks installed, some 64bit some x86. So I figured I may as well get rid of all of the x86 installations because I had reason to believe that netbeans was running one of these x86 jdk installations, (which it was), because I wasn't even getting much over 4gb of ram usage when I was overflowing my heap space while trying to find a bug.

Anyway, long story short, now it shows a straight 12GB of memory installed on the System page of the control panel, no sub-text about how only a certain amount is available. All from uninstalling some JDKs and rebooting....very odd.

The settings on dxdiag are the same as when I checked before as well. But hey, whatever works =D

Thank you for all the suggestions! especially the dxdiag command, I hadn't been aware of that before this.