What is dedicated memory?

[ahappycamper]

This may have been asked before, I apologise but I couldn't find anything.
So what is dedicated memory? For example I have an ATI Radeon 2400 HD Pro and is says it has a total of 1407mb graphics memory, 1279 system memory but only 128 dedicated graphics memory. Does this mean I would'nt be able to play a game like dead space which says it needs 256mb video card?

Also how do i download vista service pack 2, does it cost?
Thanks

 

[Nimbus]

According to this: http://ati.amd.com/products/radeonhd2400/radeonhd2400pro/index.html

It has 256MB ram.

 

[Crash486]

Dedicated memory is exactly what it sounds like. It's memory which is dedicated to performing a specific task. A shared memory video card shares its memory with the rest of the system, they are usually referred to as "onboard" video cards. Dedicated memory is memory which is actually on your video card independant of the rest of your system and is used exclusively by your video card.

Sometimes onboard cards have "dedicated" memory as well, it works the same way as the dedicated memory on a PCI-E video card would work.

 

[Kuchinawa212]

Oh two people beat me too it.

Cool looks like got what you wanted pretty quick!