How to use full 4GB RAM in Windows 7 32 Bit (Gavotte RAMDisk in Windows 7)


I was using Gavotte's edition of the Windows RAMDisk driver for a while in my windows XP installation for a while already and my results were so far really good. Using the RAMDisk driver I was able to use my full 4GB RAM in my Windows 32 Bit environment.

Question is actually: How does it work? If Microsoft limits Windows to 3GB RAM how can this be extended?

Answer: Depending on the used hardware and BIOS configuration the non-usable memory between 3GB and 4GB (this is a area for reserved addresses for physical devices) is remapped to the area above 4GB.
Windows XP/Vista/7 32Bit editions are limited to 4GB RAM addresses so the memory above 4GB is just "unused".

The Gavotte RAMDisk is able to set the RAMDisk in the area above 4GB memory addresses and can enable the usage of this area for other purposes. I use the RAMDisk for setting my page file to this area but you can also use it for setting the TEMP folder or other stuff there.

It is just important to know that the RAMDisk is not persistent - so don't store any important stuff there - every reboot or power cycle the content is lost - so temporary files can be stored very good at this location.

I came across the RAMDisk driver when reading the famous German computer magazine c't which published an article in edition 7/2009, page 78 called "Ghost-Memory" (translated from German)

Installation in of Gavotte RAMDisk in Windows 7

Step 1: Download RAMDisk Package

First you need to download the RAMDisk driver from a suitable location. Use Google to find a file called...



...unzip the content to a suitable folder.

Step 2: Enforce PAE mode in Windows 7

Open a command line with elevated right (=run as administrator) and type the command ...

bcdedit /set pae ForceEnable

Run bdcedit and validate the result. "pae" should be listed as shows below:

Command Prompt Result


Step 3: Reboot

Reboot your PC to have the PAE mode effective.

Step 4: Configure PAE mode for RAMDisk

In explorer locate the file "ram4g.reg" within the extracted set of files from the RAMDisk, double click the file to add the registry settings. The content of the REG file should look like this:

Windows Registry Editor Version 5.00


Step 5: Install RAMDisk

Navigate to the folder where the RAMDisk files have been extracted and start "ramdisk.exe" with administrator permissions.

Run ramdisk.exe as administrator

In the GUI of ramdisk.exe click on "Install Ramdisk".

After you clicked the button there will be a warning displayed by Windows Security to validate of you really would like to install the RAMDisk, click on "Install this driver software anyway".

Then... you need to wait a bit, on my box it took ~30 seconds to complete the installation. If completed the GUI should display something like:

Also you'll notice that a drive "R:\" is now available in your Windows Explorer using the size of your missing memory between 3GB and 4GB.

Step 6: Reboot (again)

Reboot (again) to validate that RAMDisk is installed correctly. After reboot the RAMDisk should be displayed in Explorer as drive R:\ again.

Step 7: Enjoy

Now you can be sure to be able to use the RAMDisk. I personally use it as swap space.

To set it up as swap space (swapping from RAM to RAM) you...

  1. Right click on "Computer" in Windows Explorer
  2. pick "Properties"
  3. then use the menu on the left for "Advanced System Settings"
  4. in the following dialog use the tab "Advanced"
  5. in the group "Performance" click the "Settings..." button
  6. on the following dialog use tab "Advanced"
  7. in the group "Virtual Memory" click on "Change..."
  8. in the following dialog (seems very advanced at this step already :-) unselect "Automatically manage paging file size for all drives" checkbox.
  9. Select your RAMDisk drive in the list box
  10. Select "Custom Size"
  11. Enter e.g. 1000 into "Initial size" box
  12. Enter e.g. 1000 into "Maximum size" box (whereas my RAMDisk had space of 1022MB available)
  13. Click on "Set" button
  14. Close the dialog with "OK"
  15. Close the dialog with "OK"
  16. Accept to reboot

After reboot you can enjoy having a computer swapping from RAM to RAM.


Gavotte_RAMDisk_1.0.4096.5_200811130.7z160.59 KB

Finally !!!

Followed the instructions, then used R:\ as swap-file (762MB-762MB).

Resource Monitor: 2715 available + 555 in use + 769 hardware reserved = total 4039

Works clear as crystal !!! Thanks very much Jens !


Sorry pal. That's exactly the

Sorry pal. That's exactly the same result you get  if the Ram disk is not installaled. Just try uninstalling the Ram disk and check the Resource Monitor again.

Just used this on win7 32

Just used this on win7 32 with 4 gigs and integrated 256 vid card (i will lower it to 64-128 tomorrow)


installed registry and then proceeded to install ,  clicked FIXED drive, didnt change the 16M and voila R drive was 768 Mb big, which is exactly the ammount of unused memory in my system (tomorrow will be  768 +128~(whatever i cut from the Integrated)


ive used ramdrive on other x64 systems, just for kicks, but its the first time i can actualyl use th eunused memory thanks!



feedback on PAE and Gavotte RAMDisk

Using the version of Gavotte RAMDisk you mention, I was able to load a RAMDISK using what I believe is RAM between 3GB and 4GB on my system, but without using the ForceEnable option on PAE with bcdedit. Given that PAE is supposed to be for addressing memory above 4GB on 32-bit systems, this does make sense, and since I only have 4GB of RAM, it doesn't make sense to have PAE enabled when it may result in a performance loss. It seems that the only thing required for Gavotte RAMDisk to use the 3GB+ memory is having the UsePAE option enabled in the registry. I tried changing this value to zero (disabled) and after reboot saw a 512MB (as was the setting in RAMDisk) - and noticed about the same amount being deducted from my system's available memory (as would be expected if it wasn't using the RAM above 3GB).

Also, regarding PageFile setings, I think it makes more sense to set a low initial size for the RAMdisk, such as the 16MB minimum, and a maximum size of 1000MB or similar. I think the practice of having a fixed-size paging file stems from trying to avoid fragmentation of the file on the hard disk due to its growth, but since this is a pagefile in RAM, fragmentation shouldn't be really be an issue. This also allows you to use the RAMdisk for other purposes, such as temp file storage.

Thanks for the info!