How to use all RAM in Windows: the most common situations and solutions.

Greetings, dear readers! To our great joy, prices for components are steadily creeping down, and today 8 GB of RAM on a home computer is not something out of the ordinary, but a “minimum program” for an advanced gamer.

However, the user can expect an unpleasant surprise: regardless of the amount of installed RAM and the number of sticks on the computer, the operating system does not see all the RAM.

Today we will look at why all RAM is not used and how you can deal with it.

32-bit OS

To understand the essence of the problem, we should recall a little history of the development of computer technology. I won’t go into too much detail and will try to give a brief summary. On the PC, created back in 1981, commands to peripheral devices and access to RAM were combined. The ratio of the amount of address space allocated for RAM and BIOS was adopted as 5:3.

With the introduction of the 80386 processor in 1985, address separation remained unchanged for compatibility with predecessor computers. Devices using the address space were allocated a full fourth gigabyte. At that time, such a value seemed an exorbitant figure: Bill Gates himself, the creator of Windows, stated that 640 kilobytes of RAM was enough for everyone.

This 32bit architecture became the standard by which office equipment developed over the next 20 years. In 32-bit Windows, regardless of the amount of installed memory, only 3.25 GB is available to the user - the rest is consumed by system resources. This is observed on the outdated, but still used in some places, “Piggy”, and on Windows 7, and on Windows 10.

The fact that the user can not use the entire amount of memory for his needs has been eliminated in the 64bit version of Windows. You can find out the version of Windows by finding the “Computer” item in the “Start” menu, right-clicking on it and selecting “Properties”.

Please note that due to the difference in architecture, an upgrade from a 32-bit version to a 64-bit version is not possible: a complete reinstallation of the operating system will be required. Drivers for all devices will also have to be 64-bit.

Hardware problem

It may also happen that the computer simply does not see one of the two installed RAM strips. To fix the problem, you can experiment with the slots in which these strips are installed. Often it is enough to simply swap modules or install them in other slots.

Wiping the RAM contacts with medical or industrial alcohol may also help. If this liquid is not on hand, you can wipe them with a regular stationery eraser. If the modules are installed incorrectly, the diagnostic wizard will start. You will have to install the RAM in the correct position.

Configuration Settings

If a situation arises when the user did not play tricks with the hardware, but part of the RAM became inaccessible, it is necessary to perform the following algorithm:

• Enter msconfig in the search bar and run the found file;
• In the window that opens, go to the “Download” tab and select “Advanced options”;
• In the next window, uncheck the “Maximum memory” checkbox.

After saving your changes, restart your computer and check how much memory is now being used. The method works regardless of the tasks assigned to the computer - when executing a program or in a game. Typically, modern games do not provide settings for how much RAM they are allowed to use, and in fact they are the same programs.

And I once again draw your attention to the fact that when assembling a computer yourself, focus on the DDR4 standard. You can find out how and by following the link.

This problem can occur on any Windows. Let's figure out why all the memory on the computer is not available.

Bit depth/bit depth and editions of Windows OS may have limitations

Due to the bit depth of Windows, there may be problems detecting all RAM. All Windows that are 32-bit (x86) cannot use more than 3.2 GB of RAM for operation. That is, even if you have, for example, 8GB of RAM installed, Windows 32bit will only be able to use 3.2GB of memory due to limitations. Also, some editions of operating systems may have restrictions. For example, Windows 7 home basic can only use 4GB of RAM!

Disable the Maximum Memory setting in MSCONFIG

Everything is simple here: if you were trying to increase the performance of your PC, you could enable the “Maximum memory” setting. It’s easy to disable it, go to Control Panel --> Administration --> System Configuration --> Boot tab --> Advanced settings --> uncheck Maximum memory!

Allocating memory to the integrated video card

Those who have an integrated video card can reserve RAM for it. To disable memory reservation for the integrated video card, you need to go to and turn off this setting there.

Look for the following values ​​in the BIOS:

• Display Cache Window Size
• Frame Buffer Size
• Int. Gfx Memory Size Select
• Internal Graphic Mode Select
• Internal Graphics Mode Select
• On-Chip Frame Buffer Size
• On-Chip Video Window Size
• Onboard VGA Frame Buffer
• Share Memory Size
• System Share Memory Size
• UMA Frame Buffer Size
• VGA Share Memory Size
• Onboard Video Memory Size

And disable memory reservation - DISABLE, NONE or set the minimum value as is.If you do not find such values, you will have to use Google and find these settings for your BIOS / UEFI.

Reserving memory for system needs in BIOS / UEFI

The BIOS settings have various restrictions on the use of RAM, and it is often because of them that Windows does not see all the RAM. Look for the following settings in BIOS/UEFI and change them:

• HPET Mode (if there is such a function) should be 64-bit;
  
• Memory Hole must be in Disabled state;
  
• Memory Remapping;
  
• DRAM Over 4G Remapping;
  
• H/W DRAM Over 4GB Remapping;
  
• H/W Memory Hole Remapping;
  
• Hardware Memory Hole;
  
• Memory Hole Remapping;
  
• Memory Remap Feature - all these values ​​must be in the Enabled state.

If you do not find such values, you will have to use Google and find these settings for your BIOS / UEFI. Very often, in this caseSimply resetting the BIOS settings helps, try this too.

Sometimes these values ​​cannot be found because the BIOS is outdated and then it would not hurt to update it. I showed how to do this in one of video.

What other problems could there be with identifying RAM?

If you have problems with the motherboard or the RAM itself, this can cause the same consequences; Windows will not see all the RAM. To identify problems it is worth doing Motherboard and RAM diagnostics.

Sometimes it helps to simply plug the RAM strips into the motherboard. Setting the RAM strips to dual-channel mode also helps.

Those who have non-original versions of Windows installed (assemblies) also experience problems identifying the entire RAM. Use original Windows distributions and you will not have such problems.

In this article, we will figure out how to remove the 4 GB memory limit on 32-bit versions of Windows 8 and Windows 8.1, and use all the RAM available on the computer.

Most Windows users are convinced that Microsoft's 32-bit operating systems do not support more than 4 GB of RAM. Thus, the maximum memory available in Windows 8/8.1 x86 is 4 GB. And taking into account the fact that Windows reserves part of the memory for its needs and the needs of peripheral devices (most often for a video card), about 3-3.5 GB of memory are usually available to the end user for use.

At first glance, everything is logical - the addressing limit for a 32-bit address bus is the same 4 GB. In all official documents, Microsoft indicates this is the maximum memory size supported in all client versions of the x86 system. Although in reality Microsoft is misleading everyone a little.

What is PAE and why is it needed?

PAE(Physical Address Extension - physical addressing extension) - this option of the x86 processor allows it to access more than 4 GB of physical memory. We will not delve into the technical details of PAE technology; we will simply note that this technology has been supported by all processors and directly in OS Windows for quite some time.

For example, a 32-bit version of Windows Server running on an x86 processor can use PAE to access the entire system RAM (up to 64 GB or up to 128 GB depending on the processor generation).

Let's say more, support for PAE mode has been available in the Windows kernel since Windows XP. It’s just that by default PAE is available only in server OSes, and in Windows client OSes this mode, although available, is disabled.

Note. PAE can only be used on 32-bit versions of Windows running on x86 processors compatible with this mode.

PAE Mode Limitations

• PAE does not extend the virtual address space of each process. Each process running on a 32-bit system is still limited to 4 GB of address space.

  Advice. PAE will not help increase the amount of memory available for a resource-intensive application (for example, a graphics or video editor). If there is such a need, it is better to switch to a 64-bit OS.

• When using PAE, you should note a slight decrease in system performance due to a decrease in memory access speed caused by the overhead of switching mapped pages in memory
• Some device drivers cannot work correctly in a 36-bit address space.

So, we can conclude that the upper limit of available physical memory in 32-bit versions of Windows is limited by software at the OS kernel level. And if there is a software limitation, that means it can be bypassed! How to enable PAE mode in 32-bit Windows 8.1 and use all available RAM.

A patch that includes PAE and allows you to use all RAM on Windows 8 / 8.1 x86

Enable PAE mode in Windows 8 (Windows 8.1) It won’t work using standard tools (to do this you will have to manually edit the ntoskrnl.exe kernel file in a HEX editor and re-sign it). The easiest way is to use a ready-made patch PatchPae2, which is written by enthusiast Wen Jia Liu. You can download the PatchPae2 patch. (the archive contains the patcher itself - PatchPae2.exe, its source codes and the necessary instructions).

The patch is a small command line utility that allows you to modify the kernel files of 32-bit versions of Windows to activate PAE mode, which allows you to use more than 4 GB of RAM (up to 128 GB of memory).

PatchPae2 will work with the following OS:

• Windows Vista SP2
• Windows 7 / Windows 7 SP1
• Windows 8/Windows 8.1

Note. Before installing the patch, in order to prevent conflicts, it is recommended to disable optimizers and RAM drivers. They can be activated after applying the patch and booting the system in PAE mode.

Installing PAE patch in Windows 8 / 8.1

Attention. This instruction can only be used for 32-bit versions of Windows 8 and Windows 8.1; for previous Microsoft operating systems the procedure is slightly different! Be careful!

Note. At any time, the user, after rebooting, can switch from PAE mode to normal mode, or vice versa, in the boot menu.

Important! After installing the patch, you need to be especially careful when installing Windows security updates. Because some Windows updates sometimes contain updates for the kernel; after installing them, you need to update the PAE kernel: PatchPae2.exe -type kernel -o ntoskrnx.exe ntoskrnl.exe

In addition, the problems described and may occur.

Removing the PAE patch

To remove the PAE patch from the system, you must:

1. Remove the corresponding entry from the boot menu (the easiest way to do this is with msconfig)
2. Delete files ntoskrnx.exe And winloadp.exe in the catalog %Windir%\System32.

The patch does not make any other changes to the system.

After upgrading to Windows 10, many users began to complain about the problem of using incomplete RAM. As an example, let's take a case from the Microsoft forum. When installing 6 GB of RAM in Windows 10 32, only 3.92 GB was displayed. The entire amount of RAM was inaccessible, or rather, the system simply did not see it. In some cases, reinstalling the RAM strips in places and cleaning the contacts helped solve this problem. However, in a number of cases this problem could not be solved.

Ways to configure display of all RAM on Windows 10

If you are faced with a situation where not all RAM is available on Windows 10 and you have not swapped the modules, you should follow these steps:

• Press “Win+R” and enter “msconfig”.

• The System Configuration window will open. Go to the “Download” tab. Click on the “Advanced options” button.

• A small window will open. Here you need to uncheck the “Maximum memory” checkbox.

• After saving the changes, you need to restart your computer and see how much memory is being used.

If Windows 10 does not see the full amount of RAM, you should remove the sticks from the slots and swap them. We also recommend cleaning the contacts of the RAM modules. To do this, take a rubber band and carefully wipe off dirt from the contacts.

If you insert the modules incorrectly, a post will occur when the PC boots. You will need to return the modules to their places and restart the computer. After downloading Windows 10 32 bit, you need to download the MemTest86 program and check the performance of the RAM.

If everything is fine with the modules, but Windows does not see all the RAM, you may be using an old version of the motherboard firmware and need to update the BIOS and also check some of its parameters.

• The first BIOS parameter that is responsible for stable operation of RAM is memory redistribution. In different firmware versions, this section may be named differently (Memory Hole Remapping, H/W DRAM Over 4GB Remapping, Hardware Memory Hole). Therefore, it is worth studying the instructions for the board in detail or finding a description for the version of the BIOS used.

The memory redistribution function transfers the address blocks used by expansion cards into the address space beyond 4 GB. Thus, it is possible to increase the amount of RAM (otherwise Windows10 will see 3-3.5 GB). To fully support such a volume, it is necessary to use 64-bit processors and 64-bit versions of the OS (or server versions of 32-bit operating systems that allow PAE physical address expansion). If you have less RAM, be sure to turn off this option (Disabled), as problems with the RAM may occur. Enable memory redistribution – value Enabled.

• Memory settings for AGP video aperture are the amount of memory that the system shares with the video adapter. It is necessary for displaying textures and drawing pictures. This amount of memory may not be used by the system if it is blocked by the video adapter. There is only one way to enable it: boot into BIOS, select AGP Aperture size. Standard values ​​are 32 MB, 64 MB, 128 MB and Auto. We look at how much memory the video card has and set the required value by value. Often this is 128 MB. However, you can try each of the options to see which one gives the best result.

After making all changes to the BIOS settings, you need to boot into Windows and check if the entire amount of RAM is visible. If the system still does not see the RAM, you should try inserting other modules into the slot. It is possible that the old RAM sticks have failed or are defective.

To learn why the system does not see all the RAM and how to fix it, watch the video:

It's clear.
I looked at the processor specification of my old computer on the Intel website - it says about it:
Instruction Set 32-bit
http://ark.intel.com/products/27438/Intel-Pentium-4-Processor-2_40-GHz-512K-Cache-533-MHz-FSB

In general, I read more on this topic on the Internet - I came to the conclusion that in order for Windows to see and start using 4 GB of RAM, software alone is not enough. That is, even server versions of Windows that have a full-fledged PAE (and install any patches there) will still not be able to interact with all the memory if the chipset in the motherboard does not have additional lines for interacting with the memory. Those. In order for all this to work, in addition to software support, hardware support is also needed. Here again, using the example of my old computer - it has a motherboard on the i945 chipset - the instructions for the motherboard state that up to 4 GB of memory can be installed. But in reality, no matter what you make up, it’s still impossible to use all 4 GB there. We can say that the chipset is 32-bit and it will not be able to accept addresses larger than 2^32 (that’s 4 GB), i.e. physically there are not so many cells in the microcircuit for recording the address or whatever, there are not so many lines on the board... And since the entire common address space (32-bit turns out) goes not only to RAM, but also to all devices - video, sound there, all sorts of controllers, etc. - then a certain part of the RAM remains without addresses and the system cannot interact with them. It turns out that in order to use all 4 GB of memory on a 32-bit chipset, you need to have nothing else on the board except the processor, memory and chipset - no other equipment. But why then might such a system be needed? :-)
But, for example, already on the G31 chip (it seems) there are additional 4 lines for working with memory, the address space increases to 2^(32+4) = 2^36, that is, up to 64 GB (although here too In fact, the result will not be 64, but 64 minus the amount of address space that the equipment will occupy).

In general, in the end it turns out that in order for Windows to interact with all the memory it is necessary that
1. Chipset mat. The board physically allowed the use of an address space of more than 32 bits.
2. Chipset mat. The board was able to do “memory mapping” - this is when memory cells with addresses that are occupied by equipment are assigned other free addresses from the space above the first 32 bits
3. The operating system was able to use this feature. boards (as far as I understand, the ability of the OS to use this feature of motherboards is called PAE - Physical Address Extensions).

Well, the conclusion (why it doesn’t work for many) is my conclusion and maybe I’m wrong.
This patch described in the article is only the third item listed above - software. But if the board physically does not have additional lines and does not know how to do memory redirection, then it cannot earn anything.