In addition to the compute shader test we've already covered, Civ V has several other built-in benchmarking modes, including two we think are useful for testing video cards. One of them concentrates on the world leaders presented in the game, which is interesting because the game's developers have spent quite a bit of effort on generating very high quality images in those scenes, complete with some rather convincing material shaders to accent the hair, clothes, and skin of the characters. This benchmark isn't necessarily representative of Civ V's core gameplay, but it does measure performance in one of the most graphically striking parts of the game. As with the earlier compute shader test, we chose to average the results from the individual leaders.
We've not often seen the Radeons' large theoretical edge in shader arithmetic performance translate into higher frame rates in real games, but I'd wager that's what's happening here. The GTX 570 ends up falling behind the Radeon HD 6870 as a result.
Another benchmark in Civ V focuses, rightly, on the most taxing part of the core gameplay, when you're deep into a map and have hundreds of units and structures populating the space. This is when an underpowered GPU can slow down and cause the game to run poorly. This test outputs a generic score that can be a little hard to interpret, so we've converted the results into frames per second to make them more readable.
Here's our first look at two GTX 570 cards in SLI, by the way. In this particular game, AMD's multi-GPU scaling appears to be superior to Nvidia's. Even though a single 6870 isn't nearly as quick as a GTX 570, two 6870s in CrossFireX are easily the fastest overall solution tested.