Win XP Pro and 4GB RAM

[hj2k_x]

ALL other versions of Windows i.e. Vista 32bit and Windows XP 32bit SP2 will only show 2.8 - 3.4GB.

What does that depend on?

 

[proximiti99]

Mmm, there must be sure way to work out what XP shall use before actually buying more ram. This cannot be a random that no one can explain?

 

[nihilist]

Running XP x64 (with minimal driver issues) and it sees all of my 6GB RAM.

 

[howardb]

Mmm, there must be sure way to work out what XP shall use before actually buying more ram. This cannot be a random that no one can explain?

There is a way, but it's complex - and the available RAM will "look" random, as each PC setup is different (even with the slightest differences), and what you see available is also dependent on the hardware you have, the BIOS setup, and what resources you or the system allocate.

XP SP2 32-bit uses approx. 0.5GB on boot/startup, so effectively, the maximum amount of available RAM is reduced to around 3.5GB immediately. The 32-bit environment and hardware will not let you see the full 4GB, but the 64-bit hardware would, even if running a 32-bit version of XP - it's all about the allocations and the hardware needs.

If you set your AGP Aperture allocation in the BIOS at 512MB or 256MB, the available RAM would reduce, dependent on the setup and allocation of other resources on your system. So the hardware configuration also plays a role.

In the BIOS, you would also need to enable the 4GB Memory Hole option, otherwise the system would probably not boot, or would give you a very low available RAM (i.e. 2 sticks only), again depending on the hardware setup.

From my endless testing, reboot, test, reboot, test, years ago with 4GB, 64-bit hardware and 32-bit XP, I tried many different settings, tweaking the BIOS, then the allocations, then the boot sequences and the hardware, just to see what allocates where, and I eventually gave up and accepted that if I have 4GB installed, the system would allocate the necessary resources accordingly - I found that by increasing my AGP Aperture value in the BIOS to 512MB, I had more available memory showing in the System Properties at the end of the day...

... in a nutshell, I'm happy with the settings now and have never tried to fiddle further with them, as they seem to work fine for me. If you want to "see" 4GB in the System Properties, then install a 64-bit OS, otherwise, you'll just have to live with 2.75GB to 3.5GB...

 

[bdt]

The definitive answer to this annoyance ..'s a long article, will have to go there to read it.

 

[Winga]

Thanks for the linky bdt. That was an awesome article. I'm late for work now 'cos I couldn't stop reading until I got to the end, but it has answered many of my questions

 

[cerebus]

It's absurd that Vista won't recognize more than 4gb of ram.

 

[Lino]

It all comes down to this, when 32bit computers were designed it was presumed PC's would never need more than 4GB of RAM. As a result thousands of PC's (32bit); hardware and software were built with the belief that no more than 3.5GB+ would ever be needed.

If you want to have more than 3.5GB of memory then use a 64bit operating system. Wether its Windows or Linux. (One word of caution it is possible to use various tricks to make 32bit systems see 4GB of RAM but it doesn't mean that it will use all of it)

 

[snail112]

Snail don't waste your cash on extra ram buy my Intel Core 2 Duo E6850 running at an amazing 3Ghz!

Uhm that is if your board supports Core2 Duo

Well back on topic I have upgraded to Vista 64bit and bought another 2Gig of ram and man what a difference

Windows she is flying.

I have a C2D 6420 2.13GHz. My board support up to Quad Core.

 

[Asha'man X]

This ram issue is so complex sometimes.

Consumer 32 bit versions of Windows cannot use more than 4gb of ram, and of that 4, tha range varies as pointed out in a few posts earlier, depending on things like video card memory and so on.

Certain server 32 bit versions of Windows can use more than 4 gigs, using an Intel technology called PAE (Physical Address Extension), running a special kernel as well. The results are a bit wonky from what I've heard of though, as programmers never really optimised code for it. Not that you would run a server system on your home pc anyway.

I cannot comment for 32 bit Linux, I don't know if they support PAE or not.

If you want to make use of your full 4gb, or more, you need a 64 bit processor (basically most modern processors) and a 64 bit operating system