Is there a workaround to use all 4GB of RAM?

bobkn · 15 Jun 2010

squall leonhart said:

of course not, because what it suggests is impossible for the memory subsystem of a 32bit host operating system.

There are 32 bit server versions of Windows that can handle significantly more than 4GB of RAM through PAE:

Physical Address Extension - Wikipedia, the free encyclopedia

The amount of RAM addressable by individual 32 bit applications would still be limited to 2-3 GB, but it would permit multiple applications to be run simultaneously in a larger real system memory.

I have read claims of hacks that permit enabling PAE on some desktop versions of Windows, but I've never tried one.

Seems mostly pointless, given the current availability of 64 bit Win7 and drivers for it.

bobtran · 15 Jun 2010

There are NO "Tweaks" that allow an x86 (32 bit) system to use more than 4gb of ram and the most I have heard of in actual use is 3.75gb used, never 4.0gb used. This limit was designed/built into the core of the OS many years ago and cannot be changed.

The only "Tweak" is to upgrade to x64 (64 bit). The lack of drivers used to be an issue but I haven't heard about any real issues lately and 32 bit programs will run on the 64 bit OS as a result of WOW.

Take the plunge and upgrade, You can always go back if you don't like it.

pallesenw · 16 Jun 2010

bobtran said:

There are NO "Tweaks" that allow an x86 (32 bit) system to use more than 4gb of ram and the most I have heard of in actual use is 3.75gb used, never 4.0gb used. This limit was designed/built into the core of the OS many years ago and cannot be changed.

There has been a PAE kernel available since Windows 2000. Microsoft has just chosen to limit it in all desktop editions.

Their 32bit server editions support everything from 4GB up to 128GB.

Fumz · 16 Jun 2010

I just finished a very interesting article on this very subject. Credit for this great read goes to mpcrsc562.

What is the truth, then? When someone says some such thing as that 32-bit Windows Vista is technically, physically, logicallly, architecturally, fundamentally or otherwise incapable of using all your 4GB or more of RAM, what can they mean?

A surprising number of people who claim some sort of attention as expert commentators would have you believe that using more than 4GB of memory is mathematically impossible for any 32-bit operating system because 2 to the power of 32 is 4G and a 32-bit register can’t form an address above 4GB. If nothing else, these experts don’t know enough history: 2 to the 16 is only 64K and yet the wealth of Microsoft is founded on a 16-bit operating system that from its very first version was designed to use 640KB of RAM plus other memory in a physical address space of 1MB. Some remember this history and add seemingly plausible qualifications that exceeding 4GB is possible only at the price of nasty hacks that require everyone—well, all programmers—to jump through hoops. Fortunately, Intel’s processors are a lot more advanced than the 8086 from all those years ago.

Geoff Chappell, Software Analyst - Viewer

bilzmale · 16 Jun 2010

Very interesting read. Someone needs to write a patch that does this for mere mortals like me. Or is at simple as changing boot.ini to select the alternative kernal?

Oh and as the OP I wasn't dreaming - I was sure I'd come across this before.

DeaconFrost · 16 Jun 2010

bilzmale said:

Oh and as the OP I wasn't dreaming - I was sure I'd come across this before.

You are still dreaming, because PAE was never intended for desktops, and it would lead to massive instability, thanks to drivers that wouldn't be capable.

Here's what I don't understand. The solution for you costs the exact same amount as a downloadable patch. You already have a legit Windows 7 license, so just get the x64 media, and be done with it. Problem solved...properly.

Kari · 16 Jun 2010

Interesting link, worth to follow and red, found on another thread today: http://www.geoffchappell.com/viewer....nse/memory.htm

logicearth · 16 Jun 2010

Listen OP, you have 4 GBs all these tweaks are for going above 4 GB. What you are not going to solve is that the hardware is going to use a portion of your RAM regardless! There is no stopping that, that is how the x86 platform functions. You will never get all your RAM on an x86 platform. It doesn't matter what settings you use or want advice you follow you will never see the full use of your RAM, ever.

bobtran · 16 Jun 2010

pallesenw said:

bobtran said:

There are NO "Tweaks" that allow an x86 (32 bit) system to use more than 4gb of ram and the most I have heard of in actual use is 3.75gb used, never 4.0gb used. This limit was designed/built into the core of the OS many years ago and cannot be changed.

There has been a PAE kernel available since Windows 2000. Microsoft has just chosen to limit it in all desktop editions.

Their 32bit server editions support everything from 4GB up to 128GB.

You still cannot access more than 4gb at one time and software must be written to use the expanded memory which very little software is even now. PAE also suffers from a performance hit as a result of the addressing conversion so not really your best choice. Further, as you stated, Microsoft chooses to NOT allow the use on desktops so it is a mute point.

If you want to use more than 4gb then upgrade to x64. Anything else is wishful thinking and not in the realm of normal PC users.

pallesenw · 16 Jun 2010

logicearth said:

Listen OP, you have 4 GBs all these tweaks are for going above 4 GB. What you are not going to solve is that the hardware is going to use a portion of your RAM regardless! There is no stopping that, that is how the x86 platform functions. You will never get all your RAM on an x86 platform. It doesn't matter what settings you use or want advice you follow you will never see the full use of your RAM, ever.

There is no difference between a 32 and a 64bit OS when the talk is about addressing physical memory. The remapped memory is to be found above 4G regardless of what OS you are running.