Access over 4 Gigs of Ram for 32 bit Vista and Windows 7

Joseph Salazar
Joseph Salazar used Ask the Experts™
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Have a Graphics client who would like to install and utilize more RAM.

How can I get the machines to access more than 4 gigs?

Cjoego
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Your best option is to use a 64-bit Operating System. However, some 32-bit windows systems can handle more than 3GB or RAM by using the /PAE switch in the boot.ini file.

See more info here:
http://www.microsoft.com/whdc/system/platform/server/PAE/PAEmem.mspx

What OS is your client using?
Here is another link from MS with RAM limits for their various operating systems:
http://msdn.microsoft.com/en-us/library/aa366778%28VS.85%29.aspx
Lee W, MVPTechnology and Business Process Advisor
Most Valuable Expert 2013
Commented:
You cannot - CANNOT - access over 4 GB with a Windows Vista system running a 32 bit version of Windows.  Likely, you'll be restricted to even less due to memory mappings.  The only option to use more RAM - if the app supports it - is to run it on a 64 bit version of Windows and compatible hardware.
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Commented:
Most modern processors have a 36 bit address bus and can theoretically access 64GB of RAM. But for compatibility reasons, all client versions of Windows will ignore RAM above the 4GB mark. This is by design. Many popular devices have drivers that fail badly with RAM above 4GB. The purpose of PAE is to allow access to RAM above 4GB so it will not help you on a client OS. A server OS should permit access to a full 4GB (with compatible hardware) but licensing restrictions may prevent access to more.

The only way you will access even a full 4GB of RAM with a client OS is to use a 64 bit OS.
If you really must use 32 bits a server OS may be a viable option.
Joseph SalazarVice President - Senior IT Consultant

Author

Commented:
Is there a possible Hack or some sort of software install

that will allow me to do this?

Cjoego
Commented:
There may be some sort of hack to allow more than 4GB RAM in a client OS but this would be in violation of Microsoft licensing agreements. I am quite sure that discussion of this would violate EE site rules.
PowerEdgeTechIT Consultant
Top Expert 2010
Commented:
Hack or software install ... yes, a 64-bit OS.  This is not a Microsoft thing - this is inherent to 32-bit architecture.  32 bits = ~4,000,000,000 addresses.
Commented:
Actually it is possible for an application to acess RAM above 4GB by means of AWE. But applications must be explicitly written to do this and most are not.
Joseph SalazarVice President - Senior IT Consultant

Author

Commented:
Alright Then,

Let me put it in the Politically Correct format to make you Happy:

Is there a Switch, Registry Edit or clever configuration that will allow this to happen?

Cjoego
Commented:
The use of AWE is an application configuration, not Windows. But very few applications support this. Any kind of hack that will allow 32 bit Windows to manage more than 4GB of RAM would almost certainly violate site rules and cannot be discussed here.

If you need more than 4GB RAM you need a 64 bit OS.
Sorry, but that's just the way it is.
Joseph SalazarVice President - Senior IT Consultant

Author

Commented:
I guess that's the way it is.
Question closed, I know--

But comment ID: 26451452 & ID: 26451879 only are the true answers to your question....

Think of it as asking, is it possible to fit 2.5GB of Data on a 2GB USB key..

Simply as in the decimal system, there are only 10 digits 0 to 9 & if you want to address 11, then you will have to address it with 2 digits, as there is no way of addressing 11 with a single digit in the Decimal system. So 4 GB is a limitation of a  32bit Archtecture and there is no way out of it.

Computers can't address a memory space of 4GB with 32-bit architecture as there is no memory address left left to use. The next address you try to use will be a repeat of some address already used causing a failure of the entire design.

Ravi.

Commented:
From a purely technical standpoint there is no reason why a 32 bit OS could not access as much as 64GB of RAM. Many server systems are doing just that.

32 bit processors are referred to as such because of the 32  bit virtual address space. But this is completely independent of the physical address space which is 36 bits on most processors. This allows for the addressing of up to 64GB of RAM. This is done in server systems by the use of the PAE kernel. Contrary to many uninformed sources this is not a hack. It simply adds a third level of address translation. 64 bit systems always use 4 level translation, even with less than 4GB of RAM.

Unfortunately, during early testing Microsoft discovered that many popular device drivers caused data corruption and crashes when used with more than 4GB of RAM. These drivers improperly assumed that the physical address space would never exceed 4GB. This was in spite of the fact that the relevant guidelines had been in place since the release of NT 3.1 in 1992. Many of these drivers were for older devices and would never be updated. Because of the widespread nature of the problem Microsoft decided that client systems would be limited to no more than 4GB of RAM. And since the 4GB address space had to be shared with memory mapped hardware devices the total addressable RAM would
 be even less.

32 bit client versions of Windows are hard coded to ignore any RAM above the 4GB mark. This could only be circumvented by the use of a modified kernel. Since access to Windows source code is strictly controlled the creation of such a kernel would be very difficult, and contrary to licensing restrictions.

The situation regarding servers is quite different. Here the need for large amounts of RAM is more important and these systems are managed by people why could be expected to install only compatible devices.

To access more than 4GB RAM in a client OS you must use a 64 bit OS.

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