If I'd have bought a new, good GPU 2 years ago that GPU would have been huge. In some older cases it wouldnt even fit. If I'd buy the same GPU today it would be small, just a little bit bigger than the GPU's used back in the 90's. Does the size indicate that the GPU is less powerful? My thought about this would be that the size is mainly the cooling, and since the cooling tecnology did not change in the last 2 years, it means that the newer GPU needs less cooling, less cooling most of the times translates to less power consumption.
How do for example 2 Nvidia GTX 650 (a new one and a 2 years old with same memory and specs) compare?