Windows 7 4Gb Memory

[FN-GM]

Hi,

I have 4GB of Ram in my workstation. I am running Windows 7 Enterprise x64. When i view how much memory i have it says only 3.86 is usable.

Why?

Thanks

[DAckroyd]

does the computer have onboard graphics? if so that will take some of the ram

[kmount]

Shared graphics I bet.

[tmcd35]

[snip - bad reply]

Doh - should have looked at the pic before replying!

Yeah, as others have said prob shared graphics

[FN-GM]

Hi,

It has its own graphics, our other machines have 8GB ram in and they just simply say 8GB. It used to have 3GB ram in but i stuck another stick in this is how it went.

[cookie_monster]

32 Bit Windows? DOH just re read that.

[cookie_monster]

Take a look at this link it describes an issue with x64 as well.

TabBlogger : The 3GB-not-4GB RAM problem

[tmcd35]

32 Bit Windows?

:cough: the bad reply I just gave - it's 64bit Windows!

What does the performance tab in task manager say?

[mac_shinobi]

I would either say one of the following

1 - shared graphics as per above

2 - its using some for the system

3. - windows is not reporting the correct amount of memory - so if you use siw or another util does that report the correct amount of memory ?

Not sure if 2 is related to 1

[cookie_monster]

The link I posted above explains the issue ^


and here http://support.microsoft.com/kb/929605/en-us

This behavior is the expected result of certain hardware and software factors.

Various devices in a typical computer require memory-mapped access. This is known as memory-mapped I/O (MMIO). For the MMIO space to be available to 32-bit operating systems, the MMIO space must reside within the first 4 GB of address space.

For example, if you have a video card that has 256 MB of onboard memory, that memory must be mapped within the first 4 GB of address space. If 4 GB of system memory is already installed, part of that address space must be reserved by the graphics memory mapping. Graphics memory mapping overwrites a part of the system memory. These conditions reduce the total amount of system memory that is available to the operating system.

The reduction in available system memory depends on the devices that are installed in the computer. However, to avoid potential driver compatibility issues, the 32-bit versions of Windows Vista limit the total available memory to 3.12 GB. See the "More information" section for information about potential driver compatibility issues.

If a computer has many installed devices, the available memory may be reduced to 3 GB or less. However, the maximum memory available in 32-bit versions of Windows Vista is typically 3.12 GB.

Pretty much saying in more detail what others have said above.

[somabc]

open msconfig, go to the boot tab and click 'advanced options' and uncheck 'max memory'

[mac_shinobi]

The link I posted above explains the issue ^

Was just reading through the article and was just about to say that lol *cough*

Thanks for that post +1 rep to you

Also Not sure if its the same with windows 7 but I know they had a similiar issue with I think windows XP Service Pack 2 ?

or at least one of the service packs that was not reporting the correct amount of memory but I think its more so what that article explains hence the link

[FN-GM]

open msconfig, go to the boot tab and click 'advanced options' and uncheck 'max memory'

This doesnt work.

Thanks for the links guys i will read them when i get chance.

Cheers

[tmcd35]

I've just read through the MS link in Cookie_Monsters reply. It basically covers the known 3Gb memory hole with 32bit Windows - the other 1Gb is needed for DMA use by the PCI bus.

However this paragraph probably applies to 64bit installs...

The BIOS must support the memory remapping feature. The memory remapping feature allows for the segment of system memory that was previously overwritten by the Peripheral Component Interconnect (PCI) configuration space to be remapped above the 4 GB address line. This feature must be enabled in the BIOS configuration utility on the computer. View your computer product documentation for instructions that explain how to enable this feature. Many consumer-oriented computers may not support the memory remapping feature. No standard terminology is used in documentation or in BIOS configuration utilities for this feature. Therefore, you may have to read the descriptions of the various BIOS configuration settings that are available to determine whether any of the settings enable the memory remapping feature.

Sooo, the BIOS does not support (or is not set to) remap certain PCI address spaces above the 4Gb threshhold. Thus this is taken away from your addressable memory.

[DAckroyd]

have you got your motherboard drivers and other drivers on the machine ok cos that Experiance Index looks very low for a computer with 4GB of ram and a 3GHz CPU