dave1701
New Member
87dtna, the reason is simple. You only lose the availability of system RAM when there is a requirement for the 32bit OS to address a total memory array above 4GB.
For example
GPU 1GB
Other stuff, sound card, HDD, DVDRAM drive etc etc = 500MB (to make it simple)
System RAM = 4GB
Now that is a total of 5.5GB that windows has to deal with. It can only address a max of 4GB (2^32). It will fully address the GPU, 1GB, and the other stuff 500MB. That 1.5GB of addressable memory is no longer available for system RAM, leaving on ly 2.5GB of total sytem ram addressable space left. So on a system with 2GB, adding another 2GB of RAM effectively gains you 500MB of system ram max (ie. 4GB - 1.5 GB = 2.5GB).
Now on a system with 2GB RAM, there is still a whole 2GB of the total 4GB addressablity left. Meaning the full 2GB of system RAM can be utilised as well as the 1.5GB of other address space. Again basic maths, 2GB + 1.5GB (GPU and other) = 3.5GB. Still below the max 4GB space allocation.
To answer the OP's question though, my thoughts:
- If you install 4GB of RAM, and you have a discrete GPU or other memory space that needs to be allocated - you need a 64bit OS.
- 2GB RAM, a 32bit OS is fine and you wont see/need any thing else
- Where 4GB of RAM is installed, you will see a massive increase in performance over 32bit especially when gaming etc. My machine uses nearly 6GB of RAM (remember Windows 7 handles memory different to before and will take as much as you give it)..
Good to hear, thanks for your help.