Windows 10 32-bit uses only 3 Gbyte RAM, Despite Higher Setting in VMware

[vmxmr]

I just created a fresh Windows 10 32-bit virtual machine. No matter how I set memory in VMware Settings, Windows 10 reports only 3 Gbytes of RAM.

Why won't it configure itself for 4 Gbytes of RAM?

Here are the steps I took:

* I created and activated a new Windows 7 32-bit (pre-SP1) from an install DVD. This original Windows 7 had hardware v11, 2 cores, and 2048 Mbytes of RAM in VMware Settings.

* I mounted the Windows 10 32-bit ISO CD/DVD image, and ran the installer from within Windows 7. I did a "clean install" (do not preserve apps, data, etc.).

* I updated Windows 10 fully, and installed VMware Tools.

* I changed the memory setting several times to 6144 and 8192 Mbytes, but nothing changed.

* I also changed to hardware v12 and changed the OS type from Windows 7 to Windows 10.

Despite the changes, Windows 10 (32-bit) reports only 3 Gbytes of physical memory. I have checked systeminfo (3071 MB), System->About Settings (3.00 GB), and several other sources, and they are all self-consistent at 3 Gbytes.

The System Configuration, BOOT Advanced Options, Maximum memory box is unchecked (disabled).

Any ideas?

[Technogeezer]

32-bit versions of Windows 10 only support a maximum of 4 GB of physical memory. See the MSDN articlee "Memory Limits for Windows and Windows Server Releases" https://msdn.microsoft.com/en-us/library/windows/desktop/aa366778(v=vs.85).aspx#physical_memory_limi...

So even if you set your VM for 6 or 8 GB of memory, 32-bit Windows won't use it.

VRAM on video adapters (yes, even VMware virtual ones) reduces the amount of available memory.

If you want more available memory in your VMs, install the 64-bit version of Windows 10.

[Technogeezer]

One other thought.  Check the size of the VRAM you have assigned to the virtual graphics adapter. I just created a default Windows 10 32-bit VM, and the default shared graphics memory (or VRAM) is set to 1GB. Wondering if this is why you can only get 3GB of free memory in the VM.

You may be able to reduce the VRAM size and gain more usable memory. There will be trade-offs such as maximum resolution and color depth if you do this. But you still have the 4GB ceiling.

[vmxmr]

Hi @Technogear,

Thanks for the reply. I didn't make myself clear enough - I knew that 32-bit Windows can only address up to 4 Gbytes RAM. (Look at the bold text in my original post.)

The problem is that my freshly created 32-bit Windows 10 will only acknowledge 3 Gbytes in my virtual machine, even though it should recognize up to 4 Gbytes.

I forgot to mention it, but I did try changing shared graphics memory in VMware Settings->Display. Running only 64 Mbytes of shared graphics memory with 8 Gbytes VMware memory assigned does not change Windows from 3 Gbytes to anything else. (When I ran 32 Mbytes of shared graphics memory, the display was black. It didn't work.)

I also looked at the VMware BIOS, but did not see anything interesting there.

So far, no matter what I do, the systeminfo command reports the same 3071 MB of physical memory. The other reporting tools are consistent with that.

Any more ideas?

[a_p_ · Accepted solution]

Please take a look at VMware KB https://kb.vmware.com/kb/1014006 which explains the 3,072 MB limit, i.e. the 1,024 MB memory reservation.

from the article:

The PC architecture reserves a portion of the address space that is below 4 GB for PCI devices. This space cannot be used for system memory. Also note that this is one of the main reasons for guests not recognizing all allocated physical memory.

André

[vmxmr]

a.p.: That's the answer! It matches my experience exactly. Thank you for taking the time to respond.

Off topic:

I had trouble viewing the knowledge base document. VMware's website gave me "1 $deletedMessageForViewDocumentPage" error, and Google search results did not have a cached version for me. I found a copy of the document (not the latest version, but good enough) using the Wayback Machine at web.archive.org: VMware KB: Virtual machine memory limits and hardware versions‌ I have been seeing the same error for VMware knowledge base entries for several days. I have not tried deleting VMware cookies and caches in my browser yet.

[a_p_]

The link works for me. However, I've seen this error message a couple of times in the past, so I assume that it's a server side issue.

André