[blazesport]

I have just loaded a Tosh Sat Pro A300 with Windows XP recovery disk that came with machine. It states this machine is updateable to 4 gig ram. The machine has 2 sticks of 2gig DDR 2 Ram. In Bios it shows as 4 gig but in windows system it reads as 3gig. I have tried sticks singularly and it reads 2 gig in bios and 2 gig in Windows system. I even then tried 2 sticks from a mates laptop, both 2 gig sticks and back to 4 gig Bios with 3 gig readout in system. Any Ideas?

[pinntech]

Hi and welcome…

You have basically ran into the limitations of a 32-bit Operating System and the system’s chipsets. Essentially, you are not going to achieve the actual 4GB due to this and the only way to actually run 4GB upwards is to have a 64-bit OS.

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.

On a SLI system, since PCI-Ex graphic cards will occupy around 256MB, another 256MB will be occupied after you install a 2nd PCI-Ex graphic card. Hence, 2.75GB memory left only if two SLI cards are installed while 3.0GB memory left with one graphic card without other add-on devices.

This limitation applies to most chipsets & Microsoft Windows 32-bit version operating systems.

If you install Windows 32-bit version operating system, it is recommended that you install less than 3GB of total memory. If more than 3GB memory is required for your system, then below two conditions must be met:

1. The memory controller which supports memory swap functionality is used. Chipsets later than Intel 975X, 955X, Nvidia NF4 SLI Intel Edition, Nvidia NF4 SLI X16, and AMD K8 CPU architecture support memory swap function.

2. Windows 64-bit OS which can address more than 4GB memory.

Thanks!

Shane