Do you need 64 bit Vista for 4 gigs RAM?

Some guy told me the other day at Circuit City that if I wanted to run Vista on a system with 4 gigs RAM, I would have to have the 64 bit OS, but not if I only wanted to use 3 gigs of RAM.

Now I am confused. Is that guy full of beans, or is that correct? I have no idea what the difference would be, but am sure it would cost me more money to get the 64 bit version.

 

That does not sound right to me i must admit its always best to run ram in pairs anyway but vista should support anything upto 8GB even at dual channel i had Vista Ultimate before switching back to XP and i had 4GB of RAM in and that was fine it just didnt like odd makes of RAM.

 

32 bit versions of operating systems can only recognize up to 3.5 gigs of ram.

64 bit versions of operating systems can recognize more than 16 gigs of ram (current high end mobo max)

biddy187 is right, only that he must of been using a 64 bit version of Windows Vista/XP

 

In any 32-bit operating system, the virtual address space is limited, by definition, to the size of a 32-bit value:

2^32 = 4,294,967,296

4,294,967,296 / (1,024 x 1,024) = 4,096 (4 Gig)

Also some of this address space is used by other things such as your graphics card, meaning you cant use all of the 4GB of address space.

In any 64-bit operating system, the virtual address space is limited, by definition, to the size of a 64-bit value:

2^64 = 18,446,744,073,709,551,616

18,446,744,073,709,551,616 / (1,024 x 1,024) / 8 = 2 exabytes

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

 

64-bit OS's can access 128 GB, just depends on the mobos capabilities be it Vista or XP. 2GB is good space for Vista RAM unless you're a big power user.