I have currently upgraded my OS from Windows XP 32 bit to windows 7 64 bit ultimate and my installed RAM shows as 4 GB ( 3.05 GB Usable ). Can you please advise why the Usable RAM memory showing less in system properties?
My motherboard, processor and ram specifications as follows.. AMD 3.4 GHz FM2 A4-5300 Processor MSI FM2-A55M-E33 Motherboard Corsair DDR3 4 GB - DDR3 RAM, 1600 MHZ
As per Microsoft:
This is expected behavior on computers that are running Windows 7. The reduction in available system memory depends on the configuration of the following: The devices that are installed in the computer and the memory that is reserved by those devices The ability of the motherboard to handle memory The System BIOS version and settings The version of Windows 7 that is installed (For example, Windows 7 Starter Edition only supports 2 GB of installed memory.) Other system settings
EDIT: For example, if you have a video card that has 256 MB of on-board 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.
For more info: http://support.microsoft.com/kb/978610
