Human Revolution kicks off with an extended engine-driven cut-scene, which would provide us with a totally like-for-like test, but as it's mostly indoors with limited effects and characters, it's no surprise that both versions run this very smoothly at the target 30FPS. So here's another test that aims to replicate the same conditions on both games: a simple traversal run from the Sarif headquarters over to the police station - a journey that puts the streaming tech through its paces and includes a couple of areas we know to stress the engine.
The conclusion is fairly obvious - both versions appear to drop frames in almost exactly the same places, and there's no real advantage to be found during the run of play. Bearing in mind the sophistication of the engine, the sophistication of the geometry and the superb lighting scheme, it's quite an achievement to have the game running effectively like-for-like on both console platforms. However, the lack of consistency on frame-rate in both versions of the game is a little disappointing. It definitely affects combat (stealth, not so much) but during basic traversal around the environments, there is a sense of judder that does rankle. The immersion in this beautiful world is compromised a little.
It's also worthwhile to point out that while Human Revolution's engine has much in common with state-of-the-art console shooters like Halo: Reach and Killzone 3, it is missing an important visual component the other games have: motion blur. The result of this is that frame-rate drops are more easily picked up by the human eye, and the sense that you're looking at a slideshow is heightened when the engine is really under stress. Again, it's worth pointing out that both console versions of the game are the same in this respect.
As you would hope for and expect, the PC version of Deus Ex: Human Revolution offers up the chance to power past the deficiencies of the console hardware and provide the best all-round experience - a pleasant surprise bearing in mind that Eidos hived off PC development to Tomb Raider collaborators, Nixxes.
We tried the game on two different i7 systems with top-of-the-line GTX580 graphics cards, one running the full retail version of the game and the other using supplied review code (console versions were final pressed copies, by the way) and found that the review version seemed to drop frames for no apparent reason on one machine. However, the other PC with the actual shipping code seemed to be buttery smooth with only small issues on the outdoor city scenes - doubly strange bearing in mind that both were Steam downloads.
In the video above, you can see how the game looks compared to the Xbox 360 version in a re-run of the original Face-Off comparison footage from the beginning of the article, and there's a PS3 vs. PC video to check out as well. Overall impressions on the PC game are impressive: even running at 720p, the graphics feel crisper and smoother than the console versions and the very important lighting seems to be more nuanced, perhaps suggesting that the computer game runs with a higher precision framebuffer.
Adding to the notion that Human Revolution is running a deferred rendering engine is the fact that the PC version of the game offers no multi-sample anti-aliasing modes whatsoever. Engines with this type of design can require colossal amounts of memory, which is the principal reason why titles such as the Dead Space games feature no AA at all - even on PC. With Deus Ex, what you do get instead is an exhaustive range of post-process AA techniques both old and new. With these techniques, the final framebuffer is processed as a 2D plane, eliminating the memory requirement, but introducing the possibility of additional artifacting - particularly on sub-pixel detailing.