Windows 7 7022 x64 4GB Memory Bug?

[ShortFuse]

My Intel 945 board worked fine with 4GB. What model are you using?

Are you sure task manager reports 4096mb of memory?

And of course the CPU is 64bit. Vista x64 and Win7 x64 wouldn't have installed if it wasn't.

Bios says 3.25GB available, 4GB Installed.

Bios also says Nvidia card has a dedicated 64mb of RAM (as I thought)

No option for memory hole. It's the stupid 32bit memory controller. The CPU controller is 64bit so I can run 64bit instructions but there's not way to get more than 3.25GB of ram. At least, somehow, dxdiag reports (but the BIOS doesn't) that the video card has 1065MB of RAM so it's being put to use somewhere.

Edited March 3, 2009 by ShortFuse

[Eric Veteran]

Are you sure task manager reports 4096mb of memory?

And of course the CPU is 64bit. Vista x64 and Win7 x64 wouldn't have installed if it wasn't.

I'm positive. I've used 4GB of RAM for a few years now. I had an 945GTP with a Pentium D 830 and under x64 all memory was available.

[ShortFuse]

I'm positive. I've used 4GB of RAM for a few years now. I had an 945GTP with a Pentium D 830 and under x64 all memory was available.

IBM says (concerning their Lenovo laptop)

Note: Only 64-bit operating systems support more than 3GB of system memory (RAM). Intel Chipsets 945GM and 945PM do not support more than 3GB system memory (RAM), even when a 64-bit operating system is installed.

Maybe it's only the 945GM and 945PM?

CpuID says I have a 945PM :(

[nautiqueskier]

k there are two reasons for the numbers you are getting

First, some Intel 945 chipsets still operate in the 32-bit address space. They will run an x64 OS and everything but do not have >4GB of mapping available. If this is the case, than any Video Card memory AND any resource mappings take away from the 4GB ram available to the system. In addition, Intel (for various reasons) have permanently reserved 1024MB for resource mappings (which is where the 3GB total memory limit comes from). This is different from many chipsets that only allocate resource mappings as needed.

There is a second factor however. Any dedicated video card ram must also be mapped. This takes away from the ram limit imposed by the chipset. So regardless of whether its dedicated or shared, the Ram mapped by the graphics card MUST be taken away from that 3GB limit.

Windows 7 Build 7000 (like Windows Vista SP1) faked the system into showing the installed amount of ram, instead of the useable amount of ram. As far as I know this was done to appease system builders. Windows 7 7022 now shows actual useable ram (like Windows Vista Pre-SP1) which is more accurate.

Here is an example. My laptop has a 945M chipset. It has 4GB of Ram installed (but Windows 7 7022 says only 2.75GB is available to use) This is because:

Intel 945M can only address 4096MB total. 1024MB is immediately taken away for resource mappings, leaving 3072MB for memory mappings. I then have a 256MB video card (dedicated but doesn't matter), which reduces the available Ram mappings from 3072 to 2816MB. 2816MB / 1024 = 2.75GB, the amount of Ram available to my system as reported by Windows 7 build 7022.

So why do I have 4GB of Ram installed in my system? If the most my system can access is 2.75GB, the only way to operate that in dual channel mode is 2x2GB modules.

Hope this helps

Edited March 3, 2009 by Ames

[charles48864]

Little more on this on page 17 and 24 The 945 had alot of flavors

http://support.intel.com/Assets/PDF/datasheet/307502.pdf