4GB memory shows 3GB on T500/XP?

Hello, I have a T500 with 3GB memory and a T400 with 3GB memory too. I replaced the 1GB memory card in T500 with the 2GB memory card from T400.

Then I went to Control Panel-> System. The system reports 2.96G RAM.

Is this right? Only Vista supports 4GB memory, correct?

Thanks, David

 

Only 64-bit operating systems will display 4GB. That means XP-Pro 64-bit all 64-bit versions of Vista, and 64-bit windows 7.

32-bit versions of XP, Vista, and Windows 7 will report 3GB-3.75GB depending on the machine. They "sort of" support 4GB; what they do is use the space between 3GB and 4GB to load device drivers and some other processes. However, they cannot address all 4GB for applications.

 

Thanks for the explanation!

So it is normal or "correct" for my T500 to report 2.96GB RAM? It is less than 3GB-3.75GB you mentioned.

Cheers!

 

I'm assuming you have the Intel integrated graphics. If so, then some memory is being shared for video memory, thus the 2.96 instead of 3GB or whatever value would otherwise be reported.

 

Thanks so much for your through explanation! Crystal clear. Yes, my computer uses integrated graphics. I am glad that the forum always has experts like you to help out.

Regards.

 

2.96 GB is quite common on mymachine even with discrete or integrated graphics. get x64 of either vista or xp to address all the memory

i doubt the graphics steals any of the unaddressable RAM. in my opinion it have only seen it steal the addressable part of the RAM

 

To add to the confusion Microsoft decided to change approach in Vista. So in Vista 32 (as opposed to XP) Control Panel -- System reports 4.0 GB. You have to go to task manager (ctrl-alt-delete), performance tab to see what is actually used, 3GB or in my case with switchable graphics 2.5 GB.

On the Vista 64 system that i am now building, Control Panel -- System and task manager -- performance tab both show 4.0 GB.

 

hi Martin,

this is a good question, I'm right now in front of a T500 with 4 GB. Shared Graphic Mem.
If I know for sure that with XP Sp3 the not addressable memory is use for graphic I'm more fine to wait a bit for the 64 bit move on this one.
Specially because 64 bit produce sort of overhead (guess Vista compared to XP anyways) which make with "just" 4 GB a decision toward 64 bit harder.

May Win 7 64 bit is not so overloaded as Vista and would be an option?

 

I've always been confused by this. I understand why a 32-bit OS will only address a maximum of about 3.5GB, but why does my T400 with discrete GPU (intel/switchable disabled in bios) only show 3GB available? Where'd that other 0.5GB go? I thought the ATI card had its own 256MB of memory.

 

it is ~3Gb with integrated graphics. the graphics memory is in fact small enough that it won't make much difference, like 64Mb
it is ~2.5Gb with discrete graphics

the difference is taken up in addressing the discrete video card.
this is one thing that pissed me off about the T400, maybe the only thing. but my anger lasted very short, since it took me around 3 seconds to decide to switch to 64bit Vista.
I've been happy ever since with my 4Gb used almost fully

yes, MS says ~3.75 but the system architecture does not let address beyond 3Gb

so the 1Gb lost above the 3Gb has little to do with which graphics card the system is using

 

OK that explains why, despite disabling switching (and the integrated graphics), I still only get 3GB. It was indeed 2.5GB when I had switchable enabled.

Why does the T400 need 0.5GB for the discrete GPU? Is this a Vista thing, or a T400 architecture thing?

 

"Only 64-bit operating systems will display 4GB. "

Lonewolf has NOT said anything wildly incorrect because what he said was lost in non-specifics. I'll say this, 32bits equals 4 gigabytes of byte addressable memory. To put things simply in a 32 bit machine, will include exec + user space.

But there's are some caveats. Tradtionally the executive space has NOT been reported to the user in displays. MS has changed this with Vista. Let's go over that again in other ways. Executive addressing space has traditionally not been reported until recently.

What does all this mean? Well-it means that nomenclature is important in discussing this and it has be consistent across vendors.

Notice that I been largely silent.

Renee

 

Thanks, Renee.

To clarify my original statement:

"Only 64-bit operating systems will display 4GB. "

I didn't mean that only 64-bit systems would use 4GB. What I meant was that 32-bit versions of Windows display (that is, report in their system properties) less than 4GB of RAM.

It sounds like Microsoft may have made a change with Vista to report (display, in my previous words) more memory in their 32-bit versions (in which case, I'd have been incorrect on one of my points). I have run Vista long enough to troubleshoot it for others, and to find out what it was like before deleting it from my systems (note that I also tested it from Beta 1 up through RC versions prior to its release). Unlike Windows 7 (which I like a lot), Vista, even with all patches and service packs, has had poor response times on my systems, and had minor UI annoyances that sent me back to XP in a hurry. That will change with Windows 7, which I've ben running (and enjoying) since Beta 2, and which has fixed all my major gripes with Windows Vista.

I've only run the 64-bit version of Windows 7; I haven't had a need to use the 32-bit version, program compatibility has been that good. But, it appears that Microsoft is changing the way it reports RAM so as not to annoy users who feel they aren't getting what they paid for.

 

Good Morning Lonewolf and the top of the morning to you....

Yes, they are starting with Vista, from which I never had any trouble, by far it's been the solidest sytem. This is true even for their Windows 7 system which gives me troubles with gmail of all things, although I think the gmail problem is mine.

To answer the OP's question, before Vista, there was no easy way to determine much memory was being used by the Exec because it was not reported.

Renee