Win xp shows only 2 GB RAM 4x1GB installed but 3 GB if 3x 1GB is installed

[wjaekel]

Hello,
I have a 6 year old shuttle-XPC with win xp prof (32bit) SP3 installed and wanted to upgrade the base memory of 2x1 GB to 4x1GB for better Photoshop work.

If I insert 4 modules, the BIOS correctly shows 4 GB while windows says 2 GB. However, if I insert 3 of the 1GB modules, the 3 GB are correctly listed in the BIOS AND in windows. I know that windows regularily supports 3 GB, but I don't understand why it goes back to 2 GB if 4x 1GB RAM is installed. Furthermore, I set the boot.ini to userva=2600/ 3GB in order to have more RAM for PS available. I would think that at least 3 GB or 3,5 GB should be recognized if 4x 1GB is inserted. But this had no effect. The manual of the shuttle says that you can insert up to 8 GB (not for win 32bit of course)but so far I don't see a restriction by the MOBO. It has 2 black coloured and 2 red coloured memory banks. There's no information what this means. I tried to add 3x 1GB to different banks. The 3 GB are accepted and shown correctly no matter which banks I used and which of the 4 1GB modules. So any ideas, why win xp shows 3 GB correctly but goes back to 2 GB if 4 modules are inserted and how to fix this?

Thank you

Wolfgang

 

[Loksley]

As far as I know Win XP doesn' t support 4 GB memory. Try win 7 32-bit.

 

[Hawkeye22]

As far as I know Win XP doesn' t support 4 GB memory. Try win 7 32-bit.

XP 32 bit supports 4 gig. It just that hardware gets mapped into some of that memory leaving you with somewhere between 3 gig to 3.5 gig available.

@OP: If your bios has a memory remap feature, enable it.

The BIOS must support the memory remapping feature. The memory remapping feature allows for the segment of system memory that was previously overwritten by the Peripheral Component Interconnect (PCI) configuration space to be remapped above the 4 GB address line. This feature must be enabled in the BIOS configuration utility on the computer.

This link applies to XP 32 bit also.

http://support.microsoft.com/kb/929605

 

[Loksley]

Good to know. Thank you!

 

[FALC0N]

Need to provide more info on the hardware. Otherwise, we are just guessing.

Maybe the board supports only 2 GB in dual channel mode. Pulling the one chip might take the board from dual to single channel. I doubt it, but its the only thing that comes to mind.