I would imagine so memory controllers wouldn't be very efficient if they filled memory sticks one by one 😂

Whether or not the software actually benefits from that increased speed is the question.

You can also address more than 4GB of RAM on 32-bit Windows Server I believe. Or use a PAE patch for XP 32-bit.

Yes, but finding benchmarks that shows it may be... problematic for WinXP.
Regardless, extra bandwidth is always nice to have.
BTW : Memory interleaving prevents any "use just one DIMM due to RAM capacity limits" from occurring.

Dan9550 wrote on 2025-08-30, 11:47:

Or use a PAE patch for XP 32-bit.

How does this work? Is it a download? Do you think Windows XP Integral Edition already comes with it?

AndreaColombo86 wrote on 2025-08-30, 13:49:

Dan9550 wrote on 2025-08-30, 11:47:

Or use a PAE patch for XP 32-bit.

How does this work? Is it a download? Do you think Windows XP Integral Edition already comes with it?

It doesn't. I have yet to see PAE working on a 32bit system - at this point I'm thinking it's vaporware.

Yes it would work, the transfer rate of the RAM being triple channel will transfer at that rate.

PAE allows access XP can use up to 64Gb of RAM.
It will not present 64Gb of RAM to the user in the system properties page, it will show maybe 3.25Gb, and that is what each application has access to, it can however apply that 3.25Gb to each application that makes a call until the whole 64Gb is used.

PAE doesnt work how people think it does. A 64bit OS presents 64Gb because that is what each application has access to, but XP presents 4Gb per application many times until the amount is used.

That changed in later versions, so after XP SP1, as Microsoft limited it to 4Gb but that is the potential of PAE.

Socket3 wrote on 2025-08-31, 20:16:

It doesn't. I have yet to see PAE working on a 32bit system - at this point I'm thinking it's vaporware.

Every XP SP2+ that can use PAE has it enabled, because PAE is a prereq for the no-execute bit ("DEP") which was a major focus of SP2 development. As XP SP2 does, the OS can still cap physical mem at 4GB if it wants, though.

ElectroSoldier wrote on 2025-08-31, 20:40:

That changed in later versions, so after XP SP1, as Microsoft limited it to 4Gb but that is the potential of PAE.

My understanding is too many third party drivers that need to handle physical addresses (eg for bus mastering) truncated to 32 bits, so MS capped PAE-enabled XP to 4GB after all.

Socket3 wrote on 2025-08-31, 20:16:

It doesn't. I have yet to see PAE working on a 32bit system - at this point I'm thinking it's vaporware.

It does work, just look at the system when you boot from the installation disk. Not only does it support > 4GB, but also 64 CPU Sockets !

The 4GB limit is simply a M$ imposed limit, I assume the patches circumvent this. A long time ago installed 2003 x32 Enterprise Server on my ASUS P5WDG2 WS Pro and all 8GB of memory is available.

jakethompson1 wrote on 2025-08-31, 21:39:

Every XP SP2+ that can use PAE has it enabled, because PAE is a prereq for the no-execute bit ("DEP") which was a major focus of […]
Show full quote

Socket3 wrote on 2025-08-31, 20:16:

It doesn't. I have yet to see PAE working on a 32bit system - at this point I'm thinking it's vaporware.

Every XP SP2+ that can use PAE has it enabled, because PAE is a prereq for the no-execute bit ("DEP") which was a major focus of SP2 development. As XP SP2 does, the OS can still cap physical mem at 4GB if it wants, though.

ElectroSoldier wrote on 2025-08-31, 20:40:

That changed in later versions, so after XP SP1, as Microsoft limited it to 4Gb but that is the potential of PAE.

My understanding is too many third party drivers that need to handle physical addresses (eg for bus mastering) truncated to 32 bits, so MS capped PAE-enabled XP to 4GB after all.

Yes it was to do with drivers that were coded to not be able to use PAE so in SP2 they changed it to limit memory use to 4Gb over all, but pre SP2 it can use upto 64Gb of system RAM over all, but only 4Gb per program (which isnt technically right but its very early in the morning to explain it properly)

Socket3 wrote on 2025-08-31, 20:16:

It doesn't. I have yet to see PAE working on a 32bit system - at this point I'm thinking it's vaporware.

Hmm, vaporware? It does exactly what it is designed to - it allows 32bit system to use more than 4GB memory. A system which does not have artificial limitations in place that is.

I've seen plenty of systems with 32bit 2003 server with a lot of ram, like 32GB, back when 2003 server was relevant. It had to be "enterprise" though, "standard" was artificially limited to 4GB, just like XP.

AFAIK on XP the limitation exists for compatibility reasons (apart from marketing reasons that is) - some poorly written drivers stop working with more than 4GB. And probably some software too. This also makes any attempts to patch the limitation out pointless - why create issues and compromise compatibility when there are no actual benefits for xp era software? Kind of similar to how there is very little reason to run 64 bit XP...

Archer57 wrote on 2025-09-01, 08:26:

Hmm, vaporware? It does exactly what it is designed to - it allows 32bit system to use more than 4GB memory. A system which does […]
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Socket3 wrote on 2025-08-31, 20:16:

It doesn't. I have yet to see PAE working on a 32bit system - at this point I'm thinking it's vaporware.

Hmm, vaporware? It does exactly what it is designed to - it allows 32bit system to use more than 4GB memory. A system which does not have artificial limitations in place that is.

I've seen plenty of systems with 32bit 2003 server with a lot of ram, like 32GB, back when 2003 server was relevant. It had to be "enterprise" though, "standard" was artificially limited to 4GB, just like XP.

AFAIK on XP the limitation exists for compatibility reasons (apart from marketing reasons that is) - some poorly written drivers stop working with more than 4GB. And probably some software too. This also makes any attempts to patch the limitation out pointless - why create issues and compromise compatibility when there are no actual benefits for xp era software? Kind of similar to how there is very little reason to run 64 bit XP...

....witch is why I called it vaporware. Enterprise applications aside, for the consumer side I've never seen XP32 with PAE working correctly. I've managed to do it once with a 3rd party patch, but it was really buggy. Imaging devices refused to work, and so did nvidia video cards with more then 2gb framebuffer (win98 patchmem issue like symptoms).

If you guys know of a PAE patch that works correctly on winXP 32bit SP3, please share it.

red-ray wrote on 2025-08-31, 23:55:

It does work, just look at the system when you boot from the installation disk. Not only does it support > 4GB, but also 64 CPU […]
Show full quote

Socket3 wrote on 2025-08-31, 20:16:

It doesn't. I have yet to see PAE working on a 32bit system - at this point I'm thinking it's vaporware.

It does work, just look at the system when you boot from the installation disk. Not only does it support > 4GB, but also 64 CPU Sockets !

The 4GB limit is simply a M$ imposed limit, I assume the patches circumvent this. A long time ago installed 2003 x32 Enterprise Server on my ASUS P5WDG2 WS Pro and all 8GB of memory is available.

Cool to see it working on windows 7, but I'd like to see it on XP32. Do you know of a good PAE patch for SP3?

Socket3 wrote on 2025-09-01, 19:44:

red-ray wrote on 2025-08-31, 23:55:

The 4GB limit is simply a M$ imposed limit, I assume the patches circumvent this. A long time ago installed 2003 x32 Enterprise Server on my ASUS P5WDG2 WS Pro and all 8GB of memory is available.

Cool to see it working on windows 7, but I'd like to see it on XP32. Do you know of a good PAE patch for SP3?

The XP32 pre-install environment also allows > 4GB, I booted W7 x32 as it was easier for me to do this.

The best "patch" for XP32 is to install 2003 x32 Enterprise Server, it's meant to work, does work and is almost the same as XP32. Were you aware XP64 is V5.02 so is actually 2003 server?

As regards drivers then if there is an XP64 driver then chances are the XP32 one with the same version will work as for XP64 it will have been fixed to correctly setup any PHYSICAL_ADDRESS blocks.

The only hardware issue is when the hardware only supports 32-bit DMA operations and even this can usually be programmed around, I know this as I needed to do this with a video capture driver I developed.

red-ray wrote on 2025-09-02, 14:15:

The XP32 pre-install environment also allows > 4GB, I booted W7 x32 as it was easier for me to do this. […]
Show full quote

Socket3 wrote on 2025-09-01, 19:44:

red-ray wrote on 2025-08-31, 23:55:

The 4GB limit is simply a M$ imposed limit, I assume the patches circumvent this. A long time ago installed 2003 x32 Enterprise Server on my ASUS P5WDG2 WS Pro and all 8GB of memory is available.

Cool to see it working on windows 7, but I'd like to see it on XP32. Do you know of a good PAE patch for SP3?

The XP32 pre-install environment also allows > 4GB, I booted W7 x32 as it was easier for me to do this.

The best "patch" for XP32 is to install 2003 x32 Enterprise Server, it's meant to work, does work and is almost the same as XP32. Were you aware XP64 is V5.02 so is actually 2003 server?

As regards drivers then if there is an XP64 driver then chances are the XP32 one with the same version will work as for XP64 it will have been fixed to correctly setup any PHYSICAL_ADDRESS blocks.

The only hardware issue is when the hardware only supports 32-bit DMA operations and even this can usually be programmed around, I know this as I needed to do this with a video capture driver I developed.

That sounds great, I'm going to try it, thanks!

Do drivers for XP32 work on 2003 Enterprise Server? Do games run properly on it?

I remember running Win2k3 as a workstation for many years because of the 4Gb limit.

AndreaColombo86 wrote on 2025-09-02, 18:14:

Do drivers for XP32 work on 2003 Enterprise Server? Do games run properly on it?

Most drivers should work fine. Games will run properly provided they do not have any unwanted version check in their code after installing the drivers needed.

There are some caveats, however.
- Latest XP32 GeForce Experience drivers have an unconditional check for "Service Pack 3" that needs to be patched out or it will block installation using the installer. The driver itself works without issues. It's recommended to use drivers designed for Win2003 if possible.
- ASUS Xonar drivers (e.g. Essence ST/STX) won't work if you have more than 4GB RAM (Win2003 or patched WinXP). The driver will immediately BSOD the system on load.
- Hardware synth on Creative Sound Blaster family may trigger BSOD with more RAM. Use a software synth such as Coolsoft VirtualMIDISynth instead.

* SBLive! will output garbage from hardware synth with more than 2GB of RAM regardless of 32-bit or 64-bit OS. Its DMA engine was flawed for being only 31-bit. With 32-bit OS the DMA operations may also corrupt system memory leading to system services crashing as well as BSOD.
** SB Audigy/X-Fi may have fixed the issue above, but on 32-bit Win2003 or patched WinXP with 4GB or more RAM there's still a chance the hardware synth will trigger BSOD.
*** PAE-related BSOD issues will also manifest on Win2003 or patched WinXP with exactly 4GB RAM, since some of the 4GB is remapped to above-4GB address space. Only when PAE is fully disabled (~3.25GB as a result) will the possible BSOD risks disappear.

LSS10999 wrote on 2025-09-03, 02:13:

Latest XP32 GeForce Experience drivers have an unconditional check for "Service Pack 3" that needs to be patched out or it will block installation using the installer.

I didn't patch it, from Device Manager I selected Update Driver and pointed it at the extracted files.

My system works well with 2 x GeForce GTX 285 on XP-32, XP-64, 2003 Enterprise Server x32, Vista x64 and 2008 R2 Server x64. Yes, it really is quintuple boot!

I also have an option to boot 2003 and just use 2GB which is the maximum that is possible below 4GB

1[boot loader]
2timeout=10
3default=multi(0)disk(0)rdisk(0)partition(2)\Windows
4[operating systems]
5multi(0)disk(0)rdisk(0)partition(2)\Windows="WXP V5.02 SP2 x64 D:     " /FASTDETECT /NOEXECUTE=OPTIN
6multi(0)disk(0)rdisk(0)partition(3)\WIN2003="SR2 V5.02 SP2 x32 E:     " /FASTDETECT /NOEXECUTE=OPTIN /PAE
7multi(0)disk(0)rdisk(0)partition(3)\WIN2003="SR2 V5.02 SP2 x32 E: 2GB " /FASTDETECT /NOEXECUTE=OPTIN /PAE /MAXMEM=2048
8multi(0)disk(0)rdisk(0)partition(4)\Windows="WXP V5.01 SP3 x32 F:     " /FASTDETECT /NOEXECUTE=OPTIN /PAE

There looks to be nothing in the 2GB to 3GB area and I am at a loss as to why the BIOS uses a TOLM on 2GB, I guess a BIOS 🐛.

red-ray wrote on 2025-09-03, 12:58:

There looks to be nothing in the 2GB to 3GB area and I am at a loss as to why the BIOS uses a TOLM on 2GB, I guess a BIOS 🐛.

Memory Remap Feature enabled ?

agent_x007 wrote on 2025-09-03, 15:21:

Memory Remap Feature enabled ?

Thank you for the thought, I looked in the BIOS and can't see such an option, typically where is it?

It should be under Advanced/Chipset features IF it's present. I didn't saw it in user's manual, but it could get added (unhidden) with BIOS update ?
Either way, I know Intel chipsets since 955X can have it.

Example from my ASUS P45 motherboard :