|There are two types of memory used for onboard graphics - dedicated & shared.|
DEDICATED memory is a memory chip on the motherboard. It's completely separate from system RAM & is "dedicated" for graphics only. It cannot be changed or upgraded...it is what it is.
SHARED memory is "stolen" from the main system RAM for use by the graphics. The amount can be changed in the BIOS. How much can be allocated for graphics use depends on how much RAM you have installed, plus whatever limitations are built into the BIOS.
Some systems use 100% shared memory, some use 100% dedicated, & some use a combination of the two (dynamically shared). Dedicated is faster, shared is slower. If you have desktop system, you're always better off with a graphics card than with onboard graphics. If you have a laptop, you're stuck with whatever the manufacturer supplies.
message edited by riider