Is this a situation where you might need to use the /3gb switch? IIRC, XP only allocates up to 2GB RAM per user process.
From: http://support.microsoft.com/default.aspx?scid=kb;en-us;833721 /3GB This switch forces x86-based systems to allocate 3 GB of virtual address space to programs and 1 GB to the kernel and to executive components. A program must be designed to take advantage of the additional memory address space. With this switch, user mode programs can access 3 GB of memory instead of the usual 2 GB that Windows allocates to user mode programs. The switch moves the starting point of kernel memory to 3 GB. Some configurations of Microsoft Exchange Server 2003 and Microsoft Windows Server 2003 may require this switch. For more information, click the following article number to view the article in the Microsoft Knowledge Base: 823440 (http://support.microsoft.com/kb/823440/) You must use the /3GB switch when you install Exchange Server 2003 on a Windows Server 2003-based system For more information, click the following article number to view the article in the Microsoft Knowledge Base: 171793 (http://support.microsoft.com/kb/171793/) Information on application use of 4GT RAM tuning Bobby -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Winterlight Sent: Saturday, July 08, 2006 3:45 PM To: The Hardware List Subject: Re: [H] Strange windows XP GeForce 6150 X2 3800+ issue XP may be seeing it, but having a problem reporting it. Check the XP System Information tool, and see if it is reported correctly. There are issues with XP efficiently using above 2GB of RAM. Maximum PC has reported that they see no performance gain above 2GB of RAM. However, I am using 4GB or Kingston RAM in a ASUS Xeon board, 1.5 GB of it in a RAM drive for TEMP, and it works fine. But like you, XP doesn't display the 4GB anywhere except the System Information Tool. At 12:08 PM 7/8/2006, you wrote: >Hi, > >I have a system I build a while ago with an Geforce 6150 based motherboard >(Asus). We have 4GB of ECC Unbuffered memory from Kingston in the system. > >Under Linux, it picks up all 4GB (32 bit kernel, PAE). Windows XP SP2, >fresh install, will only see 1.9GB of memory. > >Any ideas on how to get XP Pro to see the memory? > > Harry
