Graphics Card Memory Bandwidth

[The_Fool]

How important is memory bandwidth these days in graphics cards when gaming only at 1920x1080? I'm just wondering since I see that the Radeon HD 7970 is at about 264 GB/s while the Geforce GTX 680 is only at about 192 GB/s. My current card is at only 128.3 GB/s. Is the bandwidth of the 7970 overkill?

[HamsterCrispy]

Been asking the same question myself when I first glanced upon the monstrous bandwith of the 7970.

Just a theory - but maybe multi-monitor setups will benefit from high memory bandwith? Perhaps the 7970 performs a lot better than the 680 on 3-4 monitors at 1080 or greater resolutions.

[tweakpower]

It is very interesting question. Memory bandwidth is important for GPU, but, it all depends how "fast" GPU is.

For example, 192 GB/s should be enough for what GTX680 is capable. Even if you go to higher resolution, you will most likely come to limitation of GPU itself, before you come into memory bandwidth limitation. If at 2x*1x resolution, GPU is unable to handle more then 30FPS then even 192 GB/s will be overkill, because it will not limit GPU.

So, with today GPU's pretty much everything beyond 100 GB/s is overkill maybe.

EDIT: It's not, because even thought you are not GPU limited, it will allow you to get some insane FPS, for example, old game, 400-600 FPS = NO PROBLEM!

EDIT2: But again, maybe it is, then we come to CPU limitation, and circle goes on... lol.

[HamsterCrispy]

I see. Very interesting and a hard to pinpoint problem we have here

I always thought that the memory bandwith would be very important and that bigger bandwith means faster FPS. :o

[BrightCandle]

The performance difference between the 7970 and the GTX 680 does narrow as you move up the resolutions to the point where in surround/eyefinity resolutions the difference is basically gone on most games. That may be that the 680 is bandwidth constrained and hence loosing performance or it could be something much more complex.

[BlackZero]

The memory bandwidth should be proportionate to memory size. At 1920x1080 you'll be hard pressed to use much more than 2GB vram so memory bandwidth would need to match that.

[djjonastybe]

- Depends on how much VRAM the game uses.
- MSAA also affects memory bandwidth I think
- Higher resolutions

The bigger your resolution the more impact this has on gaming performance. Most games or applications benefit more from core/shader performance than memory.

[The_Fool]

Originally Posted by BlackZero

The memory bandwidth should be proportionate to memory size. At 1920x1080 you'll be hard pressed to use much more than 2GB vram so memory bandwidth would need to match that.

I used to think that was true about 1GB, though. Don't worry, some new games will get there. I'm curious of how much Crysis 3 will use as I hear Crysis 2 approaches 2GB, at least at 1080p at maxed settings with DX11 and the texture pack.

[BlackZero]

2GB is the new minimum.