DK8X only finds 3.2GB out of 4GB of RAM

[defakto]

the OS could map the RAM from 3.5-4GB to a higher address space and let that be 'reserved' for 64bit compatible apps/ OS stuff .. see the iwill presentation for that too..

then again, who'd ever need more than 640KB of Ram anyway

The problem comes with 32bit hardware and direct memory access, they cannot read above the 4gig barrier. It's not an OS issue. It's going to be hardware until they completly do away with 32 bit hardware.

 

[Lazn_Work]

The problem comes with 32bit hardware and direct memory access, they cannot read above the 4gig barrier. It's not an OS issue. It's going to be hardware until they completly do away with 32 bit hardware.

I think you misunderstand, the 32 bit hardware will still get it's memory space in the under 4GB barier, but the RAM that would otherwise be lost gets mapped noncontigously to above 4GB.. true only 64bit OS's could see it, but it would still be there and not be lost.

==>Lazn

 

[evenglow]

Just wanted to comment on this thread cuz when I came across this problem it drove me nuts. If you are running XP the RAM reported by Windows will be 2GB. Edit the boot.ini with the /3GB switch and /PAE and you can have a little over 3GB available. Install SP2 and you will have exactly 3GB available, no more, no less. Even though 3 out the 4GB is being reported the missing 1GB is still being used. Run a program or something and available RAM will not change for awhile.

Keep in mind that most Windows programs can only use 2GB of RAM unless it is specifically coded for 3GB. Then it only uses 3GB.

Like Morley said, it's confusing to people especially when all the Microsoft product info says 4GB is the limit then in system properties you only see 2 or 3GB. So for most people 3GB is all good.

It's nice that Iwill made that presentation but it's not really that helpful.

 

[defakto]

Keep in mind that most Windows programs can only use 2GB of RAM unless it is specifically coded for 3GB. Then it only uses 3GB.

That's not the complete story behind it all, it goes a touch deeper. If /pae and /3gb are not enabled, windows 2000 will only allow a process to access up to 2gigs of ram before it start pushing data into the paging file. With /pae and /3gb enabled windows will go up to 16gb. However, for software to access beyong 4gig it needs to use the AWE APIs.



All that info is pulled off of this website.

http://support.microsoft.com/?id=283037