4GB DDR2 on WinXP 32bit - question

[Jito463]

Pointless is right. I'm not posting in this thread anymore, as it appears I'm not getting through anyway. I have better things to do with my time.

[mwb1100]

Hey everybody! Here's a link to a good overview of the inability of x86 32-bit processors from being able to use the entire physical 4GB of RAM in a system:

http://www.codinghorror.com/blog/archives/000811.html

Note that there are also good links to more information.
Pretty much everything is covered - Virtual vs. Physical addressing, PAE, memory mapping of video RAM, the effect of x64 processors, motherboard support.
Please read this and we can all stop the pointless sniping.

[obvious]

[Jito463]

I'm not the one spreading misinformation. I've been working on and with computers for 15 years now. I work on them for a living.

Video card RAM is NOT ADDRESSED AS SYSTEM RAM.

Whether you have 8MB of VC RAM or 2GB of VC RAM, the system can still address 4GB max, and no more. Of which, a maximum of 3GB can be addressed by applications (normally 2GB, but 3GB is possible with certain workarounds that I mentioned before).

[obvious]

The OP only had 2.75GB showing in Windows XP 32Bit which has nothing at all to do with how windows then goes on to partition that space for user/kernel mode use but anyway....

32-bit Windows can't really use more than 2GB technically

Bullshit:- By default, in a 4GB configuration, 2GB is reserved for applications and 2GB for the kernel/executive. I make that >2GB in total.

I forgot to mention, you can edit the boot.ini and make Windows allocate 3GB of the RAM for applications instead of 2GB. In the boot.ini, add /3gb to the command-line parameters.

Bullshit:- the only effect this has is to reduce availble kernel memory unless apps explicitly use IMAGE_FILE_LARGE_ADDRESS_AWARE in the process header. 99 times out of a hundred it's completely pointless and in fact counterproductive.

Umm, no. Video card RAM has NOTHING to do with system RAM....Please don't post if all you're going to do is spread crap.

Bullshit:- already covered multiple times. Please dont post if all you're going to do is spread crap.

Since you apparently don't have a clue what you're talking about, and you're completely unwilling to listen, I'm not going to bother responding. Good luck in your fantasy land.

more crap spreading

Video card RAM is addressed by the video card itself, and is not included in the system RAM count by Windows.

Major Bullshit alert.

Ok, you're not understanding the point. Your video card could have 8MB of RAM on it, and you'd still only be able to use up to 3GB max out of 4GB for applications. The amount of video card RAM has nothing to do with the limitation

OK, we're off the bullshitometer here. The max user mode space would be 2GB with or without the /3GB switch as detailed above.
You wade in here and slag off someone who's actually giving good information and then go on to give a load of false and/or misleading BS yourself. As I said earlier, you're funny.

[Jito463]

Ok, you're not understanding the point. Your video card could have 8MB of RAM on it, and you'd still only be able to use up to 3GB max out of 4GB for applications. The amount of video card RAM has nothing to do with the limitation, it's an inherent limitation in a 32-bit environment.

[lmgava]

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

Nice article, thank you

[obvious]

You're funny. So what happens when a game wants to write some texture data to the graphics card? That's right, it will use an address range under 4GB which has been set aside by the BIOS for just such actions. The graphics address space is at the top of (but within) the 4GB range and is set aside before windows decides how much RAM it can address for other purposes. That's one reason why less then 4GB will show up in system properties unless there's a memory hole function in the BIOS + you're running a 64bit system + the driver supports being hoisted.

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

If I had a video card with 512Mb or 768Mb of memory on it, it'd take up even more space in the 3Gb-to-4Gb memory map.......Power users with a hankerin' for dual graphics cards may be experiencing something of a sinking feeling, at this juncture. Yes, the 256Mb reserved for my little old graphics card means exactly what you think it means: Those two 768Mb graphics cards you can totally justify buying will eat one point five gigabytes of your 32-bit memory map all by themselves, cutting you down to a 2.5Gb ceiling before you even take the other reservations into account.

This also explains why 1Gb graphics cards haven't hit the consumer market yet. Nobody yet needs anything like that much memory on one card for any desktop computer purpose, but some people would still be very happy to pay for such a card just for the pose value. It'd eat the whole of the fourth gigabyte of their system memory, though. And then they'd probably demand their money back.

[Jito463]

No, the amount of VGA RAM has nothing to do with the 4GB limitation in Windows. It's system RAM that's limited, not video card RAM. Video card RAM is addressed by the video card itself, and is not included in the system RAM count by Windows. What you're seeing is the fact that hardware devices USE system RAM, and that's why the max you can apply towards applications in a 32-bit environment is 3GB (since the remainder is dedicated to hardware).

[obvious]

Umm, no. Video card RAM has NOTHING to do with system RAM. And SP1 made no changes in the amount of RAM Windows could handle, it's a 32-bit limitation. Please don't post if all you're going to do is spread crap.

You're completely wrong Jito463. 32bit windows of course has the 4GB limit. VGA (along with a whole bunch of other stuff) is addressed within this limit as you can see if you view "resources by connection" in device manager. This will reduce available memory unless it's hoisted above 4GB on a 64bit system.

[lmgava]

512 MB from the motherboard. (What it's used for i don't know, but most motherboards these days map 512MB ram, which if hitting the 4GB barrier makes the RAM accessible, lower)

Hi Fisker, there is something about that here.

http://blogs.msdn.com/oldnewthing/archive/2006/08/14/699521.aspx

The motherboard assigned the ROMs and the hardware devices to the physical address space between 3.5GB and 4GB (occupying 0.5GB of address space). When you start plugging in your memory chips, then, they are assigned physical addresses starting at the bottom, and then skip over the address space that has already been assigned to the hardware and ROM, then resume.

On this imaginary system, then, the 0.5GB of address space used for hardware and ROMs causes that much memory to get shoved upwards, and it ends up above the 4GB boundary.

[Novecento]

@Fisker: lol

[FISKER_Q]

Since you apparently don't have a clue what you're talking about, and you're completely unwilling to listen, I'm not going to bother responding. Good luck in your fantasy land.

Sure, i'm unwilling to listen, and so is Microsoft + assorted specialists apparently, besides the only thing you said to me was "that i shouldn't spread crap", which i did listen to.

So if i'm dreaming, then i guess i'll wake up tonight when i go to bed.

[Jito463]

Since you apparently don't have a clue what you're talking about, and you're completely unwilling to listen, I'm not going to bother responding. Good luck in your fantasy land.

[FISKER_Q]

Oh and btw, in regards to MedicD's number, this is likely the scenario:

768 MB from the video adapter.
512 MB from the motherboard. (What it's used for i don't know, but most motherboards these days map 512MB ram, which if hitting the 4GB barrier makes the RAM accessible, lower)

I myself have 3,25GB memory free out of 4GB with a 256MB 7800 and, again the same 512MB allocated to the motherboard.