What does the memory on a Graphics card do?

the system shows that graphics card memory is almost 1792MB (almost 2GB) but HWINFO64 shows 1GB why the difference

I need help on something, when i run dxdiag it shows that i have 1011MB of vram, but when i run gpu-z it shows that i have 256MB, so i dont know which one is my real vram , but my graphics card(8400gs) is overclocked from : Core Clock - 451 Mhz, Shader Clock - 1113 Mhz, Memory Clock - 266 Mhz To...

Hey i recently invested in a 1gb asus gtx 550 ti graphics card, but for some reason the total memory is 4046mb ? I'm using: m5a78L motherboard 8GB corsair RAM AMD phenom II x 4 3.4ghz I experience quite bad flickering in games that makes them unplayable. Tried old and new graphics drivers...

Silly Question, but... If you had to Choose... 1 Gb @ DDR3 vs 512 Mb @ DDR5, which would ya choose and Why...??? I'm in the Hunt for a New Card and I've been lookin' at the GeForce 220 and 240 due to Space limitations in my Gateway Frame...

curious as to why gaming graphics card seem to be stuck at maximum 1GB of ram? why not add a bunch of slots so the end user could up the ram to say 16GB or 32 or more?