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I just installed this card and now the system memory says 4GB RAM (only 3.19 usable). Is it not using it's own one GiB of RAM?

I'm running Windows 10 32 bit OS. 64bit processor.

GeForce 6100PM-M2 Mobo

Resource Monitor says 833MB reserved.

Burgi
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beauknowsdiddly
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1 Answers1

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A 32 bit OS can only address 4G different memory locations. Many items of hardware map into this address space and so reduce the number of locations, that can be used to address RAM. Any main RAM, that finds no addressable space can not be used.

Graphic cards typically fall into this category: They map a lot of their onboard RAM into the address space to allow speedy transfer of data between the Computer and the card, so the observed value is not unexpected.

By using a 64 bit OS, the adressable locations are in theory 4G times 4G, in reality much less, but still more than enough. In this case, the OS can use the mapped space from your hardware (e.g. graphics card) and the full RAM at the same time.

There exist workarounds for this, e.g. the PAE system, but this has to be correctly used in every single driver on the system to avoid hard crashes (e.g. blue screens). Since many 3rd party drivers do not implement this properly, Microsoft has chosen for newer 32 bit versions of Windows not to use PAE, which makes it simply impossible to use more than 4G adresses (system RAM + hardware reserved adresses) at the same time.

In e.g. Windows Server 2003 Data Center Edition 32 bit, this was enabled - the rationale presumably being, that enterprise-class hardware would come with well-written drivers.

Eugen Rieck
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