4 1 gig memory sticks in Win XP Home

[Andrick]

Ok, need a bit of help. Finally got my second set of Crucial Ballistix memory back from Newegg on my RMA. Install the second set bringing total system memory to 4 gigs, but WIN XP only reports 3gb installed. Checked using 3DMark 05 and it shows 1 gig in each of the 4 memory slots but only shows 3 gb total. Any ideas why it does not show all 4 gigs of memory available? System is:

MSI P6N SLI Platinum LGA 775 NVIDIA nForce 650i SLI ATX Intel Motherboard

Crucial Ballistix 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory (X2)

CORSAIR CMPSU-520HX ATX12V v2.2 and EPS12V 2.91 520W Power Supply 100

EVGA 512-P3-N841-A3 GeForce 8800GTS (G92) 512MB 256-bit GDDR3 PCI Express 2.0 HDCP Ready SLI Supported Video Card

Win XP Home SP2

Any help would be greatly appreciated

 

[Scotteq]

/facepalm


In 32 bit Windows operating systems, the total addressable space available is 4GB. If you installed total 4GB memory, the system will detect less than 4GB of total memory because of address space allocation for other critical functions, such as:

- System BIOS (including motherboard, add-on cards, etc..)
- Motherboards resources
- Memory mapped I/O
- Configuration for AGP/PCI-Ex/PCI
- Other memory allocations for PCI devices

Different onboard devices and different add-on cards (devices) will result of different total memory size. e.g. more PCI cards installed will require more memory resources, resulting of less memory free for other uses.

This limitation applies to most chipsets & Windows XP/Vista 32-bit version operating systems.

If you install a Windows operating system, if more than 3GB memory is required for your system, then the below conditions should be met:

1. The memory controller which supports memory swap functionality is used. The latest chipsets like Intel 975X, 955X, Nvidia NF4 SLI Intel Edition, Nvidia NF4 SLI X16, AMD K8 and newer architectures can support the memory swap function.

2. Windows XP Pro X64 Ed. (64-bit), Windows Vista 64, or other OS which can address more than 4GB memory.



Note: According to the latest Change Log published my Microsoft, Windows Vista 32bit SP1 will display the installed amount of RAM. This is a display change only.

 

[Andrick]

This is what I suspected was the issue, but was not sure and could not find this info. Thanks for the input. I'll be going to Vista 64 once SP1 comes out

 

[dengamle]

When that time comes, be sure to chek the ram amount in task manager, and not in system properties, so you won't be fooled by the mentioned "display change only"-feature in SP1