7970 vs 680

Honestly, im looking at the 7970 dc2 non top, and the 680 top. Which is better, even when overclocking.

The 7970 is more powerful on its own, but for multi-GPU situations, Nvidia offers a much steadier framerate. Is the 680 the 4GB model?

no.

Has amd fixed frame time problems? I heard they were bad.

On its own, a 7970 is up to 15% better than a 680, and the extra GB of frame buffer will help with higher resolutions. The only version of the 680 I would get is the 4GB model; 2GB isn't cutting it for high-end games with high-res textures. AMD, however, has pretty terrible issues in CF with the frame times. You could see as little as 2 of the frames actually processed by the GPUs in CF. SLI is much better for that, but still, notperfect.I would get a 670, personally. The 4GB 670 is about as much as a medium-end 2GB 680, and will be about the same performance, especially when you OC. If you only want one GPU, though, 7970 all the way.