It's a chipset limitation, not the CPU.

Does all modules identical ? Prob some kind of incapability .

ciornyi wrote on 2023-05-28, 18:29:

Does all modules identical ? Prob some kind of incapability .

Yes. All modules are identical. If I keep any 3 modules the total ram is 3GB. Adding a 4th module doesn't make a change

antiriad wrote on 2023-05-28, 17:41:

For some strange reason my P4SCT seems to only recognize 3GB out of 4GB Installed in the motherboard (BIOS). It is clearly state […]
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For some strange reason my P4SCT seems to only recognize 3GB out of 4GB Installed in the motherboard (BIOS). It is clearly stated that 4GB is supported on the Motherboard Manual.
All 4 modules are of the same type. If all 4 modules are install I can only see 3GB. Also If I remove one module (tried all 4 of them in each slot) I still see 3GB (BIOS).
It seems there are no bad Modules or Slots since I tried each module/slot pair in with 2GB and didn't see any issues. The CPU-Z seems to be able to see all 4 modules populated with 1GB or RAM.
This system has Win98/WinXP.

There is a onboard GPU(RAGE-XL) has only static RAM (64MB) and it is currently disabled?
The CPU is a P4 3Ghz 32bit and should have an issue with 4GB or RAM.

What could be the issue?

When you use a 32bit OS, you will not be able to use 4GB of RAM anyway. So either 3GB or 3.5GB depending on the mainboard.
The only exception are OSs with PAE, like Windows Server 2003 R2 x86.

Chipset + BIOS limitation.
Don't worry about it, it can't be bypassed on 32-bit only consumer CPUs/MBs.

CoffeeOne wrote on 2023-05-28, 21:43:

antiriad wrote on 2023-05-28, 17:41:

For some strange reason my P4SCT seems to only recognize 3GB out of 4GB Installed in the motherboard (BIOS). It is clearly state […]
Show full quote

For some strange reason my P4SCT seems to only recognize 3GB out of 4GB Installed in the motherboard (BIOS). It is clearly stated that 4GB is supported on the Motherboard Manual.
All 4 modules are of the same type. If all 4 modules are install I can only see 3GB. Also If I remove one module (tried all 4 of them in each slot) I still see 3GB (BIOS).
It seems there are no bad Modules or Slots since I tried each module/slot pair in with 2GB and didn't see any issues. The CPU-Z seems to be able to see all 4 modules populated with 1GB or RAM.
This system has Win98/WinXP.

There is a onboard GPU(RAGE-XL) has only static RAM (64MB) and it is currently disabled?
The CPU is a P4 3Ghz 32bit and should have an issue with 4GB or RAM.

What could be the issue?

When you use a 32bit OS, you will not be able to use 4GB of RAM anyway. So either 3GB or 3.5GB depending on the mainboard.
The only exception are OSs with PAE, like Windows Server 2003 R2 x86.

So if I install Server 2003 I will be able to see full 4 megs? I am aware of the W98/Win XP imitations but I would expect the BIOS to see the full 4 Gigs.

agent_x007 wrote on 2023-05-28, 22:22:

Chipset + BIOS limitation.
Don't worry about it, it can't be bypassed on 32-bit only consumer CPUs/MBs.

This is considered Server motherboard. It supports ECC and non ECC ram.

antiriad wrote on 2023-05-29, 00:56:

agent_x007 wrote on 2023-05-28, 22:22:

Chipset + BIOS limitation.
Don't worry about it, it can't be bypassed on 32-bit only consumer CPUs/MBs.

This is considered Server motherboard. It supports ECC and non ECC ram.

With a 875P chipset and socket for only 1 CPU, it's a implementation of a 'standard' chipset with server quirks.

To actually make full use of 4GB RAM you need "Memory Hole Remapping" which is not available for this chipset. Only i965 and onwards supported this.

See 3GB Barrier. In practice, the amount of RAM you could access between 3GB-4GB varies depending on your video card as well as some other BIOS settings like AGP Aperture Size.

Ideally one could just install a pair of 1GB and a pair of 512MB making it 3GB in total, to be able to make full use of the installed memory sticks while still being able to utilize dual-channel.

This is considered Server motherboard

Actually workstation.

CoffeeOne wrote on 2023-05-28, 21:43:

When you use a 32bit OS, you will not be able to use 4GB of RAM anyway. So either 3GB or 3.5GB depending on the mainboard.
The only exception are OSs with PAE, like Windows Server 2003 R2 x86.

To add to this : PAE won't help you if BIOS can't adress full memory (if you don't see 4GB/4096MB available under BIOS - you are screwed).

agent_x007 wrote on 2023-05-29, 05:22:

CoffeeOne wrote on 2023-05-28, 21:43:

When you use a 32bit OS, you will not be able to use 4GB of RAM anyway. So either 3GB or 3.5GB depending on the mainboard.
The only exception are OSs with PAE, like Windows Server 2003 R2 x86.

To add to this : PAE won't help you if BIOS can't adress full memory (if you don't see 4GB/4096MB available under BIOS - you are screwed).

Every Intel 865 chipset + 915 chipset board Iv used has been limited to 3.25gb so that makes alot of sense.

Until recently i owned this board: https://www.gigabyte.com/Motherboard/GA-8I865 … -G-RH-rev-1x#ov which is a very late implementation of the 865 chipset (no C2D support, but still lga 775). When equipped with 4 gb of ram, would detect ~3.7 gb (3.67..) with a Nvidia videocard and ~3.5 gb (3.4..) with a ATI videocard, at post.