3gb of memory missing?

[Guest]

Hello,
I just built a PC with a Asus P6T SE motherboard and 6gb of memory. They are installed correctly and they show up in the slots but windows only shows 3gb of available memory. Any ideas why?

 

[clarkjd]

What version of Windows? Is it 32 bit or 64 bit?

 

[sebastian869]

Hello,
I just built a PC with a Asus P6T SE motherboard and 6gb of memory. They are installed correctly and they show up in the slots but windows only shows 3gb of available memory. Any ideas why?

same question as to the win verison and u can have a bad chip. Remove them all and simply place one in the first slot closes to the CPU(slot 1 look it up in the manual) and boot the comp and see if it registers correct and repeat for the other sticks.

 

[FALC0N]

I think you guys got it right the first time. Your likely using a 32 bit Operating system xyndicate, which can only address 4 gb's of RAM. Problem is that a portion of that is used to address hardware, so you usually end up with somewhere around 3.2 GB usable.

There is a way around this limitation. Its called PAE (physical address extension). But Microsoft does not allow PAE to extend memory on their desktop operating systems.

I have read that you can enable the PAE memory extention in Vista and presumably 7. No luck on XP. And I have no info on Linux PAE if that is your OS.

64 bit OS can address far more memory so the issue does not effect any 64 bit OS.

 

[amnotanoobie]

There is a way around this limitation. Its called PAE (physical address extension). But Microsoft does not allow PAE to extend memory on their desktop operating systems.

PAE does not work in this case. You can't make it "unuse" addresses which are used on different devices. For example, the OS needs to have an address for the memory on the video card, your LAN card, sound card, etc.

 

[FALC0N]

PAE doesn't work because microsoft locks it down. It adds 36 bit memory addressing which would simply extend the hardware addressing above 4 gb, allowing the full 4 GB to be accessible.

Wait I may have misunderstood. Are you saying the hardware addressing won't move?

 

[FALC0N]

In any case, IF the 32 OS issue is the problem you best bet is to install a 64 bit os.

 

[amnotanoobie]

PAE doesn't work because microsoft locks it down. It adds 36 bit memory addressing which would simply extend the hardware addressing above 4 gb, allowing the full 4 GB to be accessible.

Wait I may have misunderstood. Are you saying the hardware addressing won't move?

Read up on the 2nd post: http://www.tomshardware.com/forum/237090-44-showing-25gb-vista

Unless you could tolerate a few bsod's or some general trouble, you should really stop tweaking with the PAE. In my case, it really just does nothing and I'm still stuck with 3GB. (And if you're trying to be smart,) I know it's not a hardware problem as I have tried the Win 7-64 beta on it and it shows the whole 4GB.

 

[FALC0N]

I have not worked with PAE myself. Haven't had a use for it, nor an extra machine with 4gb plus to experiment with.

The only reason I can think of for it not to work it for the OS not to remap itself above 4 gb for some reason. I have heard of a few people doing it and your the first to report trouble.

I know the memory extentions are enabled in some versions of windows. Windows 2003 Enterprise for example.