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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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  • In your BIOS, confirm that your your CPU-integrated GPU is disabled or that it is set to use minimal ram. Without knowing your motherboard model, its not possible for us to tell you more. – Frank Thomas Dec 31 '15 at 02:08
  • Your first problem is a 32bit OS, and having 4gb of real memory. If you had a 64bit OS it would have spare addresses to use, but you don't. There might be a setting in the BIOS to minimize the mapped buffer. Windows also reserves certain regions for its own needs, which is another reason to go 64bit OS. – cybernard Dec 31 '15 at 02:27
  • Thank you! @FrankThomas I thought the mobo info I originally posted was the motherboard model, no? I went into my bios and under advanced chipset it says "shared memory auto detection" set to auto. I disabled that and under shared memory size was 64mb. I disabled that. Now that changed my usable RAM from 3.19gb to 3.50gb. Was that what you were referring to? – beauknowsdiddly Dec 31 '15 at 03:01
  • @cybernard can I upgrade to a 64 bit OS without losing my data and programs? – beauknowsdiddly Dec 31 '15 at 03:02
  • You can move your data to another drive, and if you have the installers the software can be re-installed. Technically, if you made sure not to format the drive during install, you wouldn't have to move your data. However, to error on the side of caution is always best. – cybernard Dec 31 '15 at 03:21
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    Possible duplicate of [Why does Windows only show about 3.5 GB of my more than 4 GB of RAM?](http://superuser.com/questions/27086/why-does-windows-only-show-about-3-5-gb-of-my-more-than-4-gb-of-ram) – DavidPostill Dec 31 '15 at 11:12

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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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