explanation of shared ram use for GPU and system ram.

[bgunner]

my system specs are in my signature at the bottom of the post.

I understand what the dedicated ram is for on the GPU itself and what the ram is for the system but why is there shared ram for a CPU with out GPU integrated and no integrated graphics on the motherboard?

where I am seeing this is in Display, Screen resolution, then clicking on Advanced Settings.

I see Total Available Graphics Memory 6869 MB

Dedicated Video Memory 3072 MB

System Video Memory 0 MB

shared System Memory 3797 MB

Why is there shared memory when there is more than enough dedicated memory?

EDIT: Windows 7 Home Premium x64

 

[skit75]

Because your video memory has to be addressed by your system memory. If you buy a video card with 1GB of memory, it gets physically addressed or mapped by your system memory (6GB of system memory in my case) giving me a working memory of only 5GB. It can best be explained by reading this: http://en.wikipedia.org/wiki/Memory-mapped_I/O

 

[bgunner]

Thank you for the link you provided it was very informative. Although i found it little tough reading at first but eventually understood it. 🙂