DX9 vs. DX11, Conclusion
DX9 vs. DX11: It Depends On Where You Look
Deus Ex: Human Revolution takes advantage of DX11, but it does so in a way that makes us think the engine's support for high-detail open spaces is limited. Take a look at the difference between DX9 and DX11 in a small space.
Once Adam steps into the wider world, the visual difference between the two API's largely evaporates. The major distinction comes down to soft shadows, which Human Revolution only supports through DX11. The shift back towards DX9 rendering for city environments might go unremarked if it weren't for a few glaring issues—like cars.
You could drop that model in the original game and it'd scarcely look out of place. There are a few other shortcuts (like the overhead tram cars) that look more like they might have been last-minute changes to improve performance. Either that, or it's some sort of ironic social commentary.
We recently discussed the problems surrounding Crytek's DX11 implementation in Crysis 2. Thankfully, there's no sign of similar abuses in DX:HR; the game's overall use of tessellation is fairly subtle.
Tessellation improves the model's three-dimensional structure, but doesn't make a huge difference. Gamers still using DX9 don't need to worry about a second-class play experience.
In-game performance mirrors what we saw between how DX11 is used indoors vs. outside. We ran two basic benchmarks. In the first, we ran a loop through the Detroit area multiple times and captured the average framerate. For the second, we fought through a battle in a large warehouse. The benchmarks below were performed using a Radeon 5970 with all detail levels maxed out relative to the API in use. DX11 used soft shadows and tessellation; Edge AA was enabled in both cases, while Vsync was turned off.
Gamers looking to improve framerates on lower-end cards should consider disabling ambient occlusion (SBAO) and opting for normal shadows.
Human Revolution isn't perfect. Neither was the first Deus Ex. The voice acting is of variable quality and the game's first few missions virtually require a stealthy approach due to Jensen's baseline squishiness. Save game loads and level transitions take a consistent 40 seconds on a conventional hard drive. That doesn't sound like much the first time, but it adds up very quickly when you're trying to sneak through an area without being spotted or testing various approaches to a room full of bad guys.
The criticisms are valid, but the game transcends its flaws. If you liked the original Deus Ex, or you think you'd like it based on its description, buy this game. Sometimes, it's just that simple.