Windows Operating Systems and Physical RAM in excess of 3GB

With many Windows users installing now more than 3GB of physical RAM, this is increasingly becoming an issue members have to deal with and come to terms with. We tested theWindows operating systems indicated below.

Test System Specifications

Intel Core 2 Duo E6600 2.40 GHz 4 MB L2 Cache
ASUS P5B Deluxe WiFi/AP
2 X 1024 MB OCZ GOLD PC2-6400 DDR2 800 MHz (Non-ECC)
2 X 1024 MB Transcend PC2-6400 DDR2 800 MHz (Non-ECC)
NVIDIA GeForce 7900 GS 512 MB DDR3

Windows XP Professional X86 (32-Bit)

Even with SP2 Windows XP just does not have the capacity to use more than 3GB or physical RAM. There are boot.ini and application switches which permit certain applications to do so. In terms of the operating system itself though, this limitation prevails no matter what boot.ini switch one uses.

With Memory Remapping enabled in the BIOS (allows full identification of more than 3GB by the BIOS), the operating system is unable to use beyond 2GB of RAM



Disabling Memory Remapping (has the effect of limiting the BIOS identification of RAM to 3GB) lets the OS use more than 2GB of RAM, but limited to a maximum of 3GB



Windows Server 2003 Enterprise SP1 X86

Windows Server 2003 Enterprise SP1 X86 with RAM remapping set to Enabled in the BIOS it has no issues at all reading the full 4GB.

With remapping Disabled, it reverts back to 3GB simply because the BIOS only reflects 3GB with that setting. The 512 MB RAM GPU causes no issues at all and is read with its full RAM available.



Windows XP Professional X64 Edition

Windows XP Professional X64 Edition also has no issues. This screenshot is before any driver installation but the same applied after all drivers were installed. I mention the drivers because I've been reading on other forums that drivers can use address space and thereby reduce the amount of RAM identified, but this seems not to have impacted on Windows XP Professional X64.

Windows Vista Ultimate Edition X86 (32-Bit)

Windows Vista Ultimate RTM X86 with memory remapping enabled, in other words with exactly the same hardware and settings as were used for Windows Server 2003 Enterprise X86 and Windows XP Professional X64 does NOT have the ability to read more than 2GB of RAM

When memory remapping is disabled though, 3GB of RAM show up

The fact that Windows Server 2003 Enterprise X86 and XP Pro X64 with the same settings (Memory Remapping Enabled), were able to show and utilize all 4GB of RAM, indicates to me that this is a Software/Operating System limitation in Window Vista Ultimate X86.


Windows Vista Ultimate Edition X64 (64-Bit)

Here's Windows Vista Ultimate X64. As with Windows Server 2003 Enterprise X86 and Windows XP Professional X64 Edition, it has no problems running 4GB of physical RAM:

Other Windows Vista x64 Editions

Large memory support for other editions of Windows Vista X64 was not tested. HERE is information provided by Microsoft about them.

Hardware and BIOS Limitations

Despite claims by some motherboard manufacturers that the chipset used supports 4GB or more of physical memory, it has been found that is not always the case. All memory controller chipsets don't have the ability to map more than 3GB. Motherboards with a BIOS which does not provide an option to "Remap memory", generally do not have that ability

Registry Problems?

The Windows registry is a directory which stores settings and options for the operating system for Microsoft Windows 32-bit versions, 64-bit versions, and Windows Mobile. It contains information and settings for all the hardware, operating system software, most non-operating system software, users, preferences of the PC, etc. Whenever a user makes changes to Control Panel settings, file associations, system policies, or most installed software, the changes are reflected and stored in the registry. The registry also provides a window into the operation of the kernel, exposing runtime information such as performance counters and currently active hardware.

When faced with performance hindering registry issues, there isn't a whole lot of options to choose from ..

1- Use computer repair software to automatically scan and repair all errors within your registry.

2- Try to manually fix the registry errors through the "Registry Editor" by yourself. This option will likely end with further damage being caused to the registry.

3- Ignore the problem and wait until the errors get so bad that the computer becomes completely unstable.

As you can see, not a great deal of choices; either let the computer fall apart, "manually" cause the computer to fall apart, or get a registry cleaner and fix the computer automatically. It isn't too hard to choose, is it? Having said that, be sure to get a registry cleaner that actually does the job right and doesn't require a whole lot of user interference. Although you'll probably want to be in charge of the registry scan, it's pretty safe to say that you won't likely want to be in charge of the actual registry repairs; which would result in you having to deal with all of the technical decisions. So once again, be sure to get computer repair software that can easily handle everything for you.

Another option you may be interested in, which usually isn't the first idea to come to mind, is "System Restore". System restore is a unique tool that allows the user to rollback all system settings & registry configurations to a previous date, while at the same time preserving the user's recent files and important documents.

All you have to do is go to Start > All Programs > Accessories > System Tools > System Restore. When the window appears, simply choose a restore point and then follow the instructions to restore the previous configurations & settings. This is truly a great way to get rid of harmful registry errors, as all changes to the system, whether they were good or bad, will have been reversed, resulting in increased PC stability. However, you should know that the removal of the registry errors is not guaranteed -- in fact, complete removal of all errors may not even be possible through the system restore tool.

In order for "System Restore" to work and actually fix the PC's registry issues, you have to know when those registry errors occurred so that you can choose the correct restore point. If you choose a restore point in which the errors were already present, nothing will have changed and the errors will still be affecting the registry. Therefore, make sure you have some general idea of when those errors first appeared before you use the "Restore" feature.

If you have no clue on when the errors first originated, you're best bet is to use the best registry cleaner that can get rid of the errors for you. And honestly, it's much easier to do a basic scan and repair with a registry cleaner than it is to do a "System Restore" every time you accumulate registry errors.

Windows Registry

The need to fix a corrupt registry is something which any personal computer owner may face at any time. Perhaps in order to address whether it is important to fix a corrupt registry or not, let us first define the Windows registry. The Windows registry is a database of information about the configuration of a computer, including software, hardware as well as files and other preferences that you have set on your computer. When faced with a corrupt Windows Registry, many people wonder what causes this problem. Installing and un-installing software on your personal computer can sometimes leave unnecessary files on your computer, and this leads to reduced computer performance. As you use your PC on a day to day basis, the Windows registry size keeps growing, and this can also cause a corrupt Windows registry.

Many computer users do not know when it is time to do a registry cleanup. So, what are the symptoms of a corrupt registry, and how do you know that it is time to fix your registry? The main symptoms of registry problems are frequent system crashes, Windows errors, slow performance, hardware malfunctioning and system crashes. In most cases, running your spyware tools do not help to improve the performance of the computer. Difficulties to log into your computer and when opening your software, files and games is also another sign that it is time to fix corrupt registry. Is it safe to ignore a corrupt registry problem and what are the risks of not fixing a corrupt registry? Given the fact that the Windows registry is the central part of your computer, it is not a good idea to ignore any signs that your registry is corrupt. This problem will not go way on its own, and a corrupt registry will only get worse if not repaired.

There is also a risk that the Windows registry will be damaged up a point where it is impossible to repair it, which will mean having to buy a new computer. The crashes and freezes of your computer will occur more frequently as the condition of your windows registry deteriorates, and this will get to a point where your PC simply stops working. This means that you will probably lose your files, data, games and any other stuff that you have stored on your PC. Perhaps another important question which computer owners have is whether it is possible for them to manually fix registry problems.

The fact is that a Windows registry is large and complex. It is also a rather delicate part of a computer such that if any damage is done to it, your PC may stop working completely. It also requires a very high level of computer expertise to understand how the Windows Registry works, let alone how to repair it. Trying to repair the windows registry manually on your own is therefore a very time-consuming, daunting and risky exercise for most computer users. When your computer has developed registry problems, it does not necessarily mean that you should buy a new computer. There are several reputable Windows registry repair utility programs on the internet that any computer user can use to fix a corrupt registry. For the average computer users, it is good to know that reputable registry cleaners are easy to run and use.