The scatter plot of power and performance on the previous page has inspired me to try a bit of an experiment. This is just for fun, so feel free to skip ahead if you'd like. I'm just curious see what we can learn by mashing up some other bits of info with our overall performance data across all of the games we tested.
This one isn't really fair at all, since we haven't normalized for the chip fabrication process involved. The three GPUs produced on a 28-nm process are all vastly superior, in terms of performance per area, to their 40-nm counterparts. The difference in size between the GeForce GTX 580 and the Radeon HD 7870, for roughly equivalent performance, is comical. The GTX 680 looks quite good among the three 28-nm chips, with higher performance and a smaller die area than the 7970.
The next few scatters are for the GPU architecture geeks who might be wondering about all of those graphics rates we're always quoting and measuring. Here's a look at how the theoretical peak numbers in different categories track with delivered performance in games. What we're looking for here is a strong or weak correlation; a stronger correlation should give us a nice collection of points roughly forming diagonal line, or something close to it.
The first couple of plots, with rasterization rate and FLOPS, don't show us much correlation at all between these properties and in-game performance. The final three begin to fall into line a little bit, with memory bandwidth and ROP rate (or pixel fill) being most strongly correlated, to my eye. Notice that the GeForce GTX 680 is apparently very efficient with its memory bandwidth, well outside of the norm.
These results led to me wonder whether the correlations would grow stronger if we subbed in the results of directed tests instead of theoretical peak numbers. We do have some of that data, so...
ShaderToyMark gives us the strongest correlation, which shouldn't be too much of a surprise, since it's the most game-like graphics workload among our directed tests. Otherwise, I'm not sure we can draw too many strong conclusions from these results, other than to say that the GTX 680 sure looks to have an abundance of riches when it comes to FP16 texture filtering.