32 bit XP/Vista and RAM

Anus! · 07/17/2007, 10:13 AM

I have a question. I know the 32Bit OS can't see the full 4Gb of RAM but has anyone ever put that much (or anything over 2Gb) and see how much it actually sees? I'm thinking of adding more to my laptop which is at 2Gb now but if it will only see 2.5 I'll buy a 1Gb chip. if it will see upwards of 3Gb or even use more than that in the background somehow I'll spend the extra $40 for another 2Gb chip.

sogo · 07/17/2007, 11:22 AM

Good question, I've been wondering about this.

superpimp8612 · 07/17/2007, 12:38 PM

As far as I know, XP could see a full 4gb setup, but that was the max. Vista on the other hand can see much more than that, I'm just not sure how much more.

dazed1 · 07/17/2007, 01:00 PM

http://www.microsoft.com/smallbusine...reWindows.aspx

dazed1 · 07/17/2007, 01:02 PM

32 bit XP goes upto 3.2gb (i think), vista business and above, 32 bit, go upto 4gb. 64 bit vista is 16gb.

Anus! · 07/17/2007, 01:10 PM

Quote:

Originally Posted by dazed1

http://www.microsoft.com/smallbusine...reWindows.aspx

see, I heard that, but then I read stuff like this.
4GB vs. 2GB memory upgrade - Windows Vista Forums

so I'm not sure wtf reality is. that's why I wanted to see if there was someone here that actually did it.

FLiPMaRC · 07/17/2007, 01:12 PM

Quote:

Originally Posted by dazed1

32 bit XP goes upto 3.2gb (i think), vista business and above, 32 bit, go upto 4gb. 64 bit vista is 16gb.

Are you saying my home PC with Vista Home Premium is at max 2GB?

dazed1 · 07/17/2007, 01:55 PM

Quote:

Originally Posted by FLiPMaRC

Are you saying my home PC with Vista Home Premium is at max 2GB?

I believe home premium comes up to 4gb, will check

Anus! · 07/17/2007, 02:10 PM

ok here is what i've found so far on the vista forums.

vista 32bit will go up to 4Gb with something called a 3Gb switch (which I still can't figure out how to do this) but because of hardware and MB configs you might only see from 2.75Gb up to 3.5Gb. the reason is the rest is being used by hardware.

Vista 64 home will see up to 16Gb

Vista business and Ultimate 64 will see up to 128Gb.

Inferno · 07/17/2007, 02:22 PM

http://www.microsoft.com/whdc/system...AE/PAEdrv.mspx

Anus! · 07/17/2007, 02:28 PM

Quote:

Originally Posted by Inferno

http://www.microsoft.com/whdc/system...AE/PAEdrv.mspx

read that. its not for vista and there is a problem...

Quote:

Enabling PAE
To enable PAE:

• Locate the Boot.ini file, which is typically in the root folder (for example, C:/) and remove its Read-Only and Hidden attributes.

vista doesnt seem to have a boot.ini file

Inferno · 07/17/2007, 02:31 PM

How to Enable More Than 3.5 GB of Memory in 32-Bit Windows Vista · Vista Rewired

Anus! · 07/17/2007, 02:38 PM

greg you rock.

I got one ? thought. at the end it says this.

Quote:

“BCDEdit is a boot configuration editor for the command line. Using the above command youâ€™ve just enabled Physical Address Extension (PAE) which can address memory larger than 4 GB. ” -

so does that mean that as long as I only put 4Gb into the laptop that I DON'T need to even do that? or do you tink that is a typo?

Inferno · 07/17/2007, 02:41 PM

Quote:

Originally Posted by Anus!

greg you rock.

I got one ? thought. at the end it says this.

so does that mean that as long as I only put 4Gb into the laptop that I DON'T need to even do that? or do you tink that is a typo?

As far as I know, every Vista user with 4GB of RAM had to do this. Doesn't seem like a difficult process anyways.

Anus! · 07/17/2007, 02:51 PM

no, it seems easy. just weird the way some of it is worded. like the title even implies that you don't need to do it unless you want over 3.5Gb.

I think I'll go order some more from newegg now and give it a try.

Inferno · 07/17/2007, 03:10 PM

On a somewhat related news, my campus just began distributing Vista and Office 2007. I just walked into IT Help Central today and told them I quit.

Balkroth · 07/17/2007, 03:23 PM

Quote:

Originally Posted by Inferno

On a somewhat related news, my campus just began distributing Vista and Office 2007. I just walked into IT Help Central today and told them I quit.

Good call

They were trying to switch my lab over and we gave um hell for it, so we're still with XP

FLiPMaRC · 07/18/2007, 08:08 AM

Quote:

Originally Posted by Inferno

On a somewhat related news, my campus just began distributing Vista and Office 2007. I just walked into IT Help Central today and told them I quit.

scoliosis · 07/18/2007, 09:49 AM

If you have either 64 bit processor (A64 or EM64) PAE is enabled by default and will allow addressing 4GB of memory address space (notice I didn't say RAM, just memory address space). If you don't have it, you have to force enable PAE and that execute protection feature thingamy to enable 4GB memory address space.

Now that's out of the way -
XP SP2 onwards, no matter what you do, you only see 2GB of available RAM to your applications. That's MSFT's doing, they hard coded the kernel to do that so that users won't run into issues with badly written drivers. PAE enabled systems requires double pointers (or was it double address jumps, I can't remember for sure) to do DMA, but a lot of driver writers cheat and just assumes no one has more than 2GB of RAM and that all the addresses are strictly <2GB.

Vista32
Since the new Vista drivers have to be written from scratch and MSFT actually forces checks on the above issue, they allow more addressable RAM. However, the amount of RAM you will see is affected by how much other types of addressable memory you have in your system. Typical rule of thumb is Total system RAM - total video RAM - PCI address space overhead = Total addressable RAM. So say you have 4GB and you have 2 8800GTX with 768MB each, you will only ever see a MAX of 2.5GB (1.5GB of total video RAM). Sucky eh?

On my system with 4GB of system RAM, I see 2GB in XP and 3.4GB in Vista32.

Anus! · 07/18/2007, 11:53 AM

lucky for me the laptop doesn't have a video card.

scoliosis · 07/18/2007, 09:30 PM

Umm... What does it use to display then? If it's one of those onboard Intel GMA stuff, then sure, it doesn't take up the memory address, but it eats up real RAM instead

Bitter · 07/18/2007, 09:43 PM

Quote:

Originally Posted by scoliosis

If you have either 64 bit processor (A64 or EM64) PAE is enabled by default and will allow addressing 4GB of memory address space (notice I didn't say RAM, just memory address space). If you don't have it, you have to force enable PAE and that execute protection feature thingamy to enable 4GB memory address space.

Now that's out of the way -
XP SP2 onwards, no matter what you do, you only see 2GB of available RAM to your applications. That's MSFT's doing, they hard coded the kernel to do that so that users won't run into issues with badly written drivers. PAE enabled systems requires double pointers (or was it double address jumps, I can't remember for sure) to do DMA, but a lot of driver writers cheat and just assumes no one has more than 2GB of RAM and that all the addresses are strictly <2GB.

On my system with 4GB of system RAM, I see 2GB in XP and 3.4GB in Vista32.

i see 3GB of ram in task manager on xp pro sp2

Anus! · 07/19/2007, 06:24 AM

Quote:

Originally Posted by scoliosis

Umm... What does it use to display then? If it's one of those onboard Intel GMA stuff, then sure, it doesn't take up the memory address, but it eats up real RAM instead

yes, it uses up to 256Mb of RAM.

scoliosis · 07/19/2007, 06:40 AM

Quote:

Originally Posted by Bitter

i see 3GB of ram in task manager on xp pro sp2

Do you see it in the Physical Memory part? - Where are we going, and what's with the handbasket? : Who ate my memory?

If you follow the TechNet article into the driver compatibility section, you'll see this paragraph "To constrain compatibility issues, Windows XP Service Pack 2 includes hardware abstraction layer (HAL) changes that mimic the 32-bit HAL DMA behavior. The altered HAL grants unlimited map registers when the system is running in PAE mode. In addition, the kernel memory manager ignores any physical address above 4 GB. Any system RAM beyond the 4 GB barrier would be made unaddressable by Windows and be unusable in the system. By limiting the address space to 4 GB, devices with 32-bit DMA bus master capability will not see a transaction with an address above the 4 GB barrier. Because these changes remove the need to double-buffer the transactions, they avoid a class of bugs in some drivers related to proper implementation of double buffering support."

Bitter · 07/19/2007, 07:54 PM

yes, where it says physical memory, 3143384 K

scoliosis · 07/19/2007, 08:44 PM

At least according to their own docs it should happen. Maybe a new patch release recently changed the implementation.

Anus! · 07/19/2007, 09:17 PM

from what I've read, you can see over 2Gb on XP too.

Inferno · 07/19/2007, 11:39 PM

Quote:

Originally Posted by Anus!

from what I've read, you can see over 2Gb on XP too.

Up to 3.25GB in most cases.

07/17/2007, 10:13 AM	#1 (permalink)
Anus! I Wangs Join Date: Dec 2001 Location: 1-888-9-ASSHOLE Vehicle: duh Posts: 33,895	32 bit XP/Vista and RAM I have a question. I know the 32Bit OS can't see the full 4Gb of RAM but has anyone ever put that much (or anything over 2Gb) and see how much it actually sees? I'm thinking of adding more to my laptop which is at 2Gb now but if it will only see 2.5 I'll buy a 1Gb chip. if it will see upwards of 3Gb or even use more than that in the background somehow I'll spend the extra $40 for another 2Gb chip.

07/17/2007, 12:38 PM	#3 (permalink)
superpimp8612 Future M.D. Join Date: Jan 2005 Location: Louisiana Posts: 738	As far as I know, XP could see a full 4gb setup, but that was the max. Vista on the other hand can see much more than that, I'm just not sure how much more. __________________ "This is the land in which we killed Kennedy but let Bush live. For that alone we deserve to burn."

07/17/2007, 02:22 PM	#10 (permalink)
Inferno Rotary Hell Join Date: Jan 2004 Location: Carrollton, TX Vehicle: 2004 Mazda RX-8 Posts: 12,848	http://www.microsoft.com/whdc/system...AE/PAEdrv.mspx __________________ "Tell my tale to those who ask... tell it truthfully, the evil deeds along with the good, and let me be judged accordingly. The rest... is silence..."

07/17/2007, 02:31 PM	#12 (permalink)
Inferno Rotary Hell Join Date: Jan 2004 Location: Carrollton, TX Vehicle: 2004 Mazda RX-8 Posts: 12,848	How to Enable More Than 3.5 GB of Memory in 32-Bit Windows Vista · Vista Rewired __________________ "Tell my tale to those who ask... tell it truthfully, the evil deeds along with the good, and let me be judged accordingly. The rest... is silence..."

07/17/2007, 03:10 PM	#16 (permalink)
Inferno Rotary Hell Join Date: Jan 2004 Location: Carrollton, TX Vehicle: 2004 Mazda RX-8 Posts: 12,848	On a somewhat related news, my campus just began distributing Vista and Office 2007. I just walked into IT Help Central today and told them I quit. __________________ "Tell my tale to those who ask... tell it truthfully, the evil deeds along with the good, and let me be judged accordingly. The rest... is silence..."

07/17/2007, 11:22 AM	#2 (permalink)
sogo R.I.P Shavana :( Join Date: Mar 2002 Location: .org Aug 2001 Vehicle: magnum Posts: 2,764	Good question, I've been wondering about this.

07/17/2007, 01:00 PM	#4 (permalink)
dazed1 Huh ? Join Date: Mar 2001 Location: San Francisco, CA Vehicle: 08 G35 Sedan Posts: 5,052	http://www.microsoft.com/smallbusine...reWindows.aspx

07/17/2007, 01:02 PM	#5 (permalink)
dazed1 Huh ? Join Date: Mar 2001 Location: San Francisco, CA Vehicle: 08 G35 Sedan Posts: 5,052	32 bit XP goes upto 3.2gb (i think), vista business and above, 32 bit, go upto 4gb. 64 bit vista is 16gb.

07/17/2007, 02:10 PM	#9 (permalink)
Anus! I Wangs Join Date: Dec 2001 Location: 1-888-9-ASSHOLE Vehicle: duh Posts: 33,895	ok here is what i've found so far on the vista forums. vista 32bit will go up to 4Gb with something called a 3Gb switch (which I still can't figure out how to do this) but because of hardware and MB configs you might only see from 2.75Gb up to 3.5Gb. the reason is the rest is being used by hardware. Vista 64 home will see up to 16Gb Vista business and Ultimate 64 will see up to 128Gb.

07/17/2007, 02:51 PM	#15 (permalink)
Anus! I Wangs Join Date: Dec 2001 Location: 1-888-9-ASSHOLE Vehicle: duh Posts: 33,895	no, it seems easy. just weird the way some of it is worded. like the title even implies that you don't need to do it unless you want over 3.5Gb. I think I'll go order some more from newegg now and give it a try.

07/18/2007, 09:49 AM	#19 (permalink)
scoliosis &quot;I dunno&quot; guy Join Date: Jan 2002 Location: Seattle Vehicle: Audi A4 2.0t Quattro Posts: 1,186	If you have either 64 bit processor (A64 or EM64) PAE is enabled by default and will allow addressing 4GB of memory address space (notice I didn't say RAM, just memory address space). If you don't have it, you have to force enable PAE and that execute protection feature thingamy to enable 4GB memory address space. Now that's out of the way - XP SP2 onwards, no matter what you do, you only see 2GB of available RAM to your applications. That's MSFT's doing, they hard coded the kernel to do that so that users won't run into issues with badly written drivers. PAE enabled systems requires double pointers (or was it double address jumps, I can't remember for sure) to do DMA, but a lot of driver writers cheat and just assumes no one has more than 2GB of RAM and that all the addresses are strictly <2GB. Vista32 Since the new Vista drivers have to be written from scratch and MSFT actually forces checks on the above issue, they allow more addressable RAM. However, the amount of RAM you will see is affected by how much other types of addressable memory you have in your system. Typical rule of thumb is Total system RAM - total video RAM - PCI address space overhead = Total addressable RAM. So say you have 4GB and you have 2 8800GTX with 768MB each, you will only ever see a MAX of 2.5GB (1.5GB of total video RAM). Sucky eh? On my system with 4GB of system RAM, I see 2GB in XP and 3.4GB in Vista32. __________________ My Blog Last edited by scoliosis; 07/18/2007 at 09:52 AM.

07/18/2007, 11:53 AM	#20 (permalink)
Anus! I Wangs Join Date: Dec 2001 Location: 1-888-9-ASSHOLE Vehicle: duh Posts: 33,895	lucky for me the laptop doesn't have a video card.

07/18/2007, 09:30 PM	#21 (permalink)
scoliosis &quot;I dunno&quot; guy Join Date: Jan 2002 Location: Seattle Vehicle: Audi A4 2.0t Quattro Posts: 1,186	Umm... What does it use to display then? If it's one of those onboard Intel GMA stuff, then sure, it doesn't take up the memory address, but it eats up real RAM instead __________________ My Blog

07/19/2007, 07:54 PM	#25 (permalink)
Bitter am cat Join Date: May 2004 Location: Homewood, Il Vehicle: 2007 Camaro Posts: 32,091	yes, where it says physical memory, 3143384 K

07/19/2007, 08:44 PM	#26 (permalink)
scoliosis &quot;I dunno&quot; guy Join Date: Jan 2002 Location: Seattle Vehicle: Audi A4 2.0t Quattro Posts: 1,186	At least according to their own docs it should happen. Maybe a new patch release recently changed the implementation. __________________ My Blog

07/19/2007, 09:17 PM	#27 (permalink)
Anus! I Wangs Join Date: Dec 2001 Location: 1-888-9-ASSHOLE Vehicle: duh Posts: 33,895	from what I've read, you can see over 2Gb on XP too.