New Posts  All Forums:Forum Nav:

An x64 OS can't read 4GB

post #1 of 6
1/8/08 at 1:56am
Thread Starter 
Windows XP Professional x64 Edition.. it reads 3.25GB, cannot read 4GB.. the motherboard hardware supports up to 8GB... what gives?
Reply
Reply
post #2 of 6
1/8/08 at 11:00pm
if your chipset doesnt support moving the addresses to 64-bit memory space properly, it'll still remap the IO adresses for the video card, etc to the top of the 32-bit address space, still eating up the top of 4GB
Reply
Reply
post #3 of 6
1/10/08 at 8:25am
I am going to assume that you are talking about the Vostro in your signature... It has this CHIPSET which according to Intel specs should support up to 8GB of memory addressing. Then I look it up on Dell's website HERE and if you read the footnote at the bottom about the RAM...

1 Desktops configured with 4GB of Memory or More: The total amount of available memory will be less than 4GB. The amount less depends on the actual system configuration.

In all honesty I don't know why that would be, unless of course this is just a disclaimer for people trying this with a 32bit OS. Check in the system BIOS... see how much memory it says you have installed. Like my E1705 notebook has the capability to hold 4GB of RAM also, but the chipset will only address 3.25GB of it - and this is reflected in the BIOS screen. Find out what yours says and go from there. Perhaps there is an issue with x64 XP and this chipset... I would assume you downloaded and installed the proper chipset drivers for it from Dell right?

Reply
Reply
post #4 of 6
1/10/08 at 1:14pm
here's a good article on the problem:

http://www.codinghorror.com/blog/archives/000811.html

and linked in there is a MSDN article which talks about the problem:

http://support.microsoft.com/kb/929605/en-us
Reply
Reply
post #5 of 6
1/11/08 at 12:30am
Thread Starter 
The BIOS reads 4GB, the OS does not. I haven't tried installing any other OS yet because Ubuntu apparently blacks out with my video card even on LiveCD.

Also, I understand why 32 bit only allows 3.25GB, but Im using a 64 bit OS, not 32 bit. The chipset says it supports up to 8GB, and the BIOS read it. I just don't understand why the OS doesn't read it.
Reply
Reply
post #6 of 6
1/11/08 at 12:40am
because the hardware addresses are still mapped to the 32-bit space. your only option is if your BIOS supports moving it, as described in the article I linked
Reply
Reply
New Posts  All Forums:Forum Nav:
  Return Home