need advice 8gb showing as 4gb ram

[kschmidt]

I recently put together a new build with a lanparty dk x48 motherboard, I have muskin 8gb DDR2 Ram, but it's only showing as 4gb? How can I fix this problem and make sure i'm using all 8gb of ram and having it show?

Also, I have 2 sapphire HD3870 512mb video cards linked with crossfire, and have crossfire enabled in my system, how can I make sure they are interfaced correctly and that my system is using them?

 

[PsyKhiqZero]

Where are you getting the memory reading from the OS or the BIOS? Are you using a 64bit OS? (vista x64 or xp64)

 

[kschmidt]

i'm using windows vista, 64-bit. I'm getting the reading from the OS

 

[PsyKhiqZero]

look in your bios and see if there is anything about memory remapping. I hear that i has to be enabled on some boards for vista to work.