MB Total Memory 6144MB vs. Vista 32-bit Memory 3325MB

[Tec]

Hi Friends:

I have an Intel® Desktop Board D975XBX2 with the following:

Bios Version: BX9750J.86A.2802.2007.1024.1947

Processor: Intel (R) Core (TM) 2 CPU
6700 @ 2.66 GHz
Intel (R) EM64T Capable

L2 Cache RAM: 4096 KB
Total Memory: 6144 MB
Memory Mode: Dual Channel

Memory Channel A Slot 0: 2048 MB
Memory Channel A Slot 1: 1024 MB
Memory Channel B Slot 0: 2048 MB
Memory Channel B Slot 1: 1024 MB

Slot 0: Corsair XMS2 Xtreme Performance - Memory - 4 GB ( 2 x 2 GB ) - DIMM 240-pin - DDR II - 800 MHz / PC2-6400 - CL5

Slot 1: Corsair XMS2 Xtreme Performance TwinX Matched - Memory - 2 GB ( 2 x 1 GB ) - DIMM 240-pin - DDR II - 800 MHz / PC2-6400 - CL4

=======================================================

Windows Edition: Windows Vista Ultimate

System

Rating: 4.5 Windows Experience Index
Processor: Intel (R) Core (TM) 2 CPU 6700 @ 2.66 GHz
Memory (RAM): 3325 MB
System Type: 32-bit Operating System

=======================================================

My Computer (Vista) can't recognize my 6GB into the RAM-Memory...Can you help me?

Thanks

TecMan

[k0NG0]

Firstly: a 32-bit OS means it can use at maximum the memory space addressable with 32 bits, which is 4GB. Doesn't matter if you install 6GB, the OS can only address 4GB since it doesn't know how to express addresses beyond using 32 bits.

Add to that the fact that the 4GB address space is used for memory-mapped devices (PCI devices, I/O ports, essentially all of these are mapped into memory "stealing" addressable space) and you end up with less than 3.5GB of memory you can put stuff in.

If you want to break this "a bit less than 3.5GB"-limit, you will need a 64-bit OS. Then you can throw memory at the system until you're bored, and it'll have no problem addressing it. Thousands of terabytes are no problem.

[Tec]

Hi k0NG0:

Thanks for your reply...just one more question...Can I use "How to Enable More Than 3.5 GB of Memory in 32-Bit Windows"?

Steps:

1) Access cmd: Click on the Start Pearl > type cmd in the Search Bar > and press Ctrl + Shift + Enter (this allows you to run cmd in administrative mode)

2) Type BCDEdit /set PAE forceenable

Thanks

TecMan

[k0NG0]

Probably. But PAE is a hack and performance isn't very good from what I've heard.

If you really need to use more than 3.5GB of memory (very few people do) I'd say investing in a 64-bit OS is probably the best way of solving this problem.

[shaihulud]

Not only is PAE a kludge (slower) but is only supported with Windows Server based OS to address greater than 32bits. However, PAE is already enabled for DEP with Windows XP service pack 2 and as you can tell you can only address 32bits.

x64 is your only option if you are to address higher. Even if it is to be Linux or UNIX you will need a 64bit operating system. Welcome to the world of 32bits, it is limited.

[specmike]

As a temporary solution, you could get some use from the extra unseen memory by using some RAM drive software. You could have XP use the RAM drive as a paging file instead of your HD.

[shaihulud]

He cannot use it since it cannot even be addressed.

[S.SubZero]

PAE facts:

1. Workstation-grade Windows OSs are hard-coded to 4GB max. There's no way to extend this with PAE.

1. The memory taken in upper 4GB range is *still* taken with PAE. So in this user's case this won't help at all.

[shaihulud]

1. The memory taken in upper 4GB range is *still* taken with PAE. So in this user's case this won't help at all.

PAE is not used, at all, in x64 mode. When in long mode you have the ability, via the processor, to access 40bits physical and 48bits virtual. The motherboard and the operating system support will differ, of course.

[specmike]

Originally Posted by shaihulud

He cannot use it since it cannot even be addressed.

LOL.....

I should have thought before I posted. Since the RAM drive utility is OS based, you cannot build a RAM drive with memory that Windows cannot address.

Actually, IMO, it would be nice for Gigabyte to have a DDR2 I-RAM or another company with a similiar device. Even with a 32 bit OS those can make good use of extra memory.

[S.SubZero]

Originally Posted by shaihulud

PAE is not used, at all, in x64 mode. When in long mode you have the ability, via the processor, to access 40bits physical and 48bits virtual. The motherboard and the operating system support will differ, of course.

This I know, that's why I said "with PAE" since the question seemed to involved using 32-bit Windows. Like with 8GB on a PAE-enabled 32-bit Windows it won't read 8GB, it will read like 7.8GB. I often see people with 4GB RAM asking about enabling PAE so they can see all of it, but that simply doesn't work.