Only 3 out of 4GB RAM detected in Vista

[Adammk]

Hi All

I've got 4 x 1GB PC 6400 Geil sticks on my Gigabyte 96SP-DS3 board.

When booting it says that there is 4GB there, but when I get into Vista its only showing 3GB.

Any ideas why?

Many Thanks!

Adam

 

[Cutthroat]

Probably because you have 32bit Vista and it can only see 3GB RAM, you need a 64bit operating system to use 4GB.

 

[JustaGeek]

http://www.dansdata.com/askdan00015.htm

 

[imported_darkpegisus]

If that's true then why does Microsoft say you can address 4GB on 32bit operating system.

link to Knowledge Base Article.
http://support.microsoft.com/kb/929580/en-us

 

[TekDemon]

Originally posted by: darkpegisus
If that's true then why does Microsoft say you can address 4GB on 32bit operating system.

link to Knowledge Base Article.
http://support.microsoft.com/kb/929580/en-us

You can indeed address 4GB...except your video card is counted in that, along with a whole bunch of other little chunks of memory for stuff.

OP likely sees 3.xGB, not precisely 3.0GB (it's possible though, if he has other hardware that requires precisely 1GB of memory address space).

Basically that 512MB video card will take away 512MB of address space, that crazy Audigy xtreme mega hyper gamer version with crazy RAM will take away more, etc.

It's a limitation of all 32-bit operating systems, so if you want to use all 4GB of your memory you have to move to 64-bit.

 

[Eomer of Aldburg]

Hence why 3GB is the sweet spot for Vista OS 32bit

 

[wpeng]

Is that really the sweet spot? Does having more than 2GB do much at all?

 

[aka1nas]

The RAM "sweet spot" for Vista is usually about 600MB to 1GB higher than XP to account for all the new features and Aero. 2Gb is usually comfy for gaming on XP, so a bit more is noticeably better in Vista.

I can get my commit charge in Vista 64 up to around 3.75GB without too much trouble. it will happily use as much RAM as you throw at it.

 

[tcsenter]

Originally posted by: darkpegisus
If that's true then why does Microsoft say you can address 4GB on 32bit operating system.

Welcome to 2004.

 

[nyker96]

I think all 32bit OS can go to 3GB only, you probably need a 64bit version to do >3gb.

 

[SickBeast]

I'm having the same problem under Vista 64-bit.

I have 3.5gb of ram installed, but only 3.0gb shows up in windows.

In my BIOS it says '3.5gb installed' and '3.0gb usable'.

I have 3 1gb sticks and a 512mb stick.

My motherboard is an Asus A8N-E. It's frustrating, and it's apparently a known issue with both Vista and the motherboard.

 

[pallejr]

Some of the memory addresses are shared with other resources, so some of the RAM is unaddressable (the addressable amount is what bios calls usable). This can be fixed by memory remapping; can be found in bios setup. 64-bit os or 32-bit with PAE and large memory support is needed