What does more GB on a GPU do exactly?

[boozie]

I'm gonna shoot from the hip and say I would assume more RAM typically helps higher resolutions. With that in mind, how helpful is 2 GB vs 1 when gaming at 1920 x 1080?

What about with 2 monitors, playing one game in borderless windowed?

 

[Anarchist420]

It depends upon how high the color buffer precision is, how much as is used at that resolution, how high the depth and stencil buffer precision is, and how much shader and texture data is used.

A 1920x1080, r5g6b5, and d16 back buffer and no AA wont use much memory at all. That would use ~8MB.

 

[Anarchist420]

However, a back buffer of 1920x1080 with rgba16 color buffer, 32 bit depth buffer, and 4xrgmsaa on the Xbox 360 would use about ~360 MB alone without compression. Then the front buffer would 1920x1080xRGB8 which would be ~6 MB. None of the aforementioned figures include what shader and texture data would take up, however.

 

[Arkadrel]

This is what too little video memory means:

See how all the cards that have 1gb memory are around 0.5 fps?
The 1280mb 470 (1.2gb) has around 3.2 fps? (still bottlenecked)
and the 480 has just barely enough memory?

This doesnt happend often at 1920x1080, but it CAN happend.

If you want to be "future" proof, with the newer titles comeing out, and plan on gameing at 1920x1080 and have high AA, then getting a card with 1gb is too little. Esp true if you also plan on useing game mods with high-res texture packs ect.

 

[ALIVE]

This is what too little video memory means:

See how all the cards that have 1gb memory are around 0.5 fps?
The 1280mb 470 (1.2gb) has around 3.2 fps? (still bottlenecked)
and the 480 has just barely enough memory?

This doesnt happend often at 1920x1080, but it CAN happend.

If you want to be "future" proof, with the newer titles comeing out, and plan on gameing at 1920x1080 and have high AA, then getting a card with 1gb is too little. Esp true if you also plan on useing game mods with high-res texture packs ect.

why the ati card with 2gb scored 0?!?!?!? the hd 5970??

 

[toyota]

why the ati card with 2gb scored 0?!?!?!? the hd 5970??

its a crossfire card so it really only as 1gb of vram.