How is video memory used and why is it important?

[sygyzy]

Can someone explain how the 128MB, 256MB memory on board today's modern graphics cards are used? Why are they important? Why is the price difference between a card with 128MB versus one with twice the memory, is very low?

Thanks.

 

[sswingle]

Currently, no games are really using 256 mb of memory. The video memory is used to hold textures and other information, much like your system memory is used, except its just stuff pertaining to the video.


Sorry I don't have a more technical answer.

 

[Matthias99]

Video memory is used for the same reasons that any other memory is used -- to store data while it's being worked on by a processor (in this case, the GPU on the video card).

If there is not enough memory on the card, your game will have to shuffle data back and forth across the AGP bus to the main system memory (or even the hard disk, if your system memory is too small!), which hurts performance. That said, the general consensus is that none of today's games are really using more than 128MB of memory, unless you want to run at resolutions higher than 1600x1200 with AA/AF. However, 128MB is much preferable to 64MB, which itself is a big step up from 32MB.

As for your last question, the price difference between 128/256 is still pretty significant (~$100-150 for the high-end cards). They use very fast RAM, and it isn't cheap. Plus, they get to put a number that's twice as big on the box. It *must* cost twice as much, right? right?

 

[sygyzy]

Thanks for the answers. I thought the prices were closer. My coworker just quoted a $20 difference between a Radeon 9600 with those memory sizes.

So what are the largest textures used right now? Are we talking like 4MB or closer to 128MB?

 

[modedepe]

On a radeon 9600 the price difference usually isn't much. This is because they aren't putting double the amount of the same ram--they put twice as much ram but it's a lot slower. I think about the largent amount of memory that's being used in games is around for textures 90mb

 

[VIAN]

I've heard doom3 is supposed to use 80mb of textures. We still don't know however, how the resolution, bit-depth, and extra special effects are going to increase that number and by how much.

 

[MrThermistor]

>So what are the largest textures used right now? Are we talking like 4MB or closer to 128MB?

You'll need at lest a 64MB card for current games, and for next generation applications, 128MB would be preferred.

Quake I might have used 4MB of VRAM.