It maps into the address space of whatever the 64-bit address space is (8 terabytes or something like that). When you have a 32-bit OS, the address space is only 4GB, the system maps in the hardware memory (BIOS, graphics card RAM, etc.) space from the top of the address space down. That is why you get between about 3-3.5GB of actual RAM when you have 4GB RAM on a 32-bit system. I know I'm not explaining this well, so take a look here:
http://www.codinghorror.com/blog/2007/03/dude-wheres-my-4-gigabytes-of-ram.h tml and http://support.microsoft.com/kb/929605 Bobby -----Original Message----- From: hardware-boun...@hardwaregroup.com [mailto:hardware-boun...@hardwaregroup.com] On Behalf Of Gary VanderMolen Sent: Thursday, April 29, 2010 9:09 PM To: hardware@hardwaregroup.com Subject: Re: [H] Win7 Ent 32-bit vs 64-bit? So what will they map into instead? As far as I know, the video has to map into RAM, regardless if the OS is 32-bit or 64-bit. Gary VanderMolen, Microsoft MVP (Mail) -----Original Message----- From: Bobby Heid IIRC, the BIOS and video RAM will not have to map into the 4GB address space (in 64-bit). He will have the whole address space for RAM.
