December 17th, 2011

By Andrew Burnes

Batman: Arkham City has been available on the consoles for some time, racking up awards left, right and center, and a 96% Metacritic rating too. Now, the PC version is available, and in this article we’ll examine the included enhancements, run benchmarks on the game using our 500-Series GPUs, recommend Optimal Playable Settings, and show how to enhance your frame rates by repurposing older NVIDIA video cards that may be gathering dust on a shelf somewhere.

Graphics Options

Like any good PC game, Batman: Arkham City allows you to enable and disable numerous graphical effects, so whether you’re looking to increase your frame rate, or simply to eliminate motion blur, you control how the game looks.

The Batman: Arkham City configuration panel where every in-game effect can be enabled and disabled.

General Graphics Options

In addition to the configurable PhysX, DirectX 11, 3D Vision and anti-aliasing options, a number of other settings can be enabled and disabled. Here’s a quick rundown of what you gain and lose when adjusting the ‘Detail Level’ preset:

Quality Preset	Very High	High	Medium	Low
Texture Quality	High	Medium	Medium	Low
Dynamic Lights	Enabled	Enabled	Enabled	Enabled
Dynamic Shadows	Enabled	Enabled	Enabled	Disabled
Motion Blur	Enabled	Enabled	Disabled	Disabled
Distortion	Enabled	Enabled	Disabled	Disabled
Lens Flares	Enabled	Enabled	Disabled	Disabled
Light Shafts	Enabled	Enabled	Disabled	Disabled
Reflections	Enabled	Enabled	Disabled	Disabled
Ambient Occlusion	Enabled	Disabled	Disabled	Disabled
Max Shadow Resolution	512	512	512	256

 

And here’s a brief description of each setting:

• Dynamic Shadows: Shadows that change based on the movement of characters and the lighting around them. Disabling this effect should be a last resort in search of performance.
• Motion Blur: Helps accentuate exciting and fast-paced elements of the game and adds to the overall spectacle. Some users may prefer to disable it simply because they favor a ‘clean’ experience.
• Distortion: Creates effects such as heat haze, as can be seen in real life.
• Lens Flares: Responsible for the stylistic use of halos when looking at bright lights and the sun.
• Light Shafts: Used to simulate bright light shining down into a dark room or area through a crack or gap.
• Reflections: An explanation isn’t required, even for The Joker’s brain-dead goons!
• Ambient Occlusion: A basic DirectX 9 and 10 version of the DirectX 11 HBAO ambient occlusion feature, this setting renders soft shadows created by reflected light sources.
• Dynamic Lights: A hidden setting, Rocksteady leaves this enabled even on Low. Disabling it manually had no perceivable impact on frame rates, but did make the visuals reminiscent of last-gen games.
• Max Shadow Resolution: Another hidden setting that determines the quality of all shadows in Arkham City. Can be manually raised to 2048 on high-end GPUs to sharpen shadows.
• Texture Quality: Linked to the ‘Detail Level’ option, this hidden setting adjusts the quality of textures in the game. By manually disabling the options visible in the configuration panel, one can leave ‘Detail Level’ on Very High to benefit from improved textures without the performance hit of the visual effects.

Click to view an animated comparison showing each detail level. Note the loss of Ambient Occlusion’s richer, more accurate shadows around the pallet in the lower right of the image.

DirectX 11 Tessellation

Just about everything in the game is drawn using triangles. Tessellation is a technique that divides large triangles into many smaller triangles, and when used with displacement mapping, significantly improves the geometric detail of objects. Tessellation has many uses depending on the game genre. In Battlefield 3, for example, it improves the detail of mountains and terrain. In Batman: Arkham City, tessellation is used to add extra definition to organic, curved and bendy objects, such as trees and power cables.

As you can see in the example above from Poison Ivy’s lair, there is a significant fidelity improvement between Tessellation Off and Normal on the deformed tree, and a further improvement going from Normal to High.

To achieve this effect an artist examined the tree, deciding where extra detail would help enhance the scene, and then created a texture containing the bumps and their physical heights, as seen when tessellation is enabled. This texture, known as a displacement map, is loaded into the game and the extra detail created on top of the basic tree using the graphics card’s DirectX 11 features.

Click for an animated comparison highlighting the three levels of tessellation.

As mentioned, GPU-powered tessellation is also utilized on cables, pipes and trees untouched by Ivy’s poison. The common trait between these three examples is curvature, something that is ordinarily too ‘expensive’ to produce using standard polygons.

In this enhanced PC release, Arkham City also makes use of a second tessellation technique called Mesh Smoothing to add tessellated triangles to break up harsh angular outlines, adding curvature where previously the object was comprised of many straight surfaces in an attempt to create the appearance of curvature. It’s a subtle addition, but once you know it’s there and you’ve seen the improvement you won’t want to go back.

Hardware Accelerated PhysX Effects

In a dilapidated environment like the eponymous Arkham City you expect to see debris, be that discarded rubbish, tattered materials, or loose masonry fallen from a crumbling building. And though other games have presented this level of detail in cityscapes in the past, most render these objects as static items baked into the scenery’s textures, and as immovable items fixed in place by the world’s strongest superglue.

Enabling ‘Hardware Accelerated PhysX’ in the game’s launcher adds these details, all of which are rendered as physical objects, able to be manipulated realistically in real-time. Newspapers tumble along the streets in concert with the wind, bunting flutters, and ropes dangle. Each can be further manipulated by the actions of Batman, his enemies, and his numerous gadgets. And being physics-led objects they don’t clip through the terrain or other objects, so given the correct circumstances said newspapers may end up wrapped around a street lamp by the driving wind or in a corner with leaves and other simulated objects. This realistic collision detection is the most intensive element of PhysX, requiring the power of the graphics card’s CUDA cores to determine the outcome of thousands of calculations per second to ensure that the a piece of paper doesn’t ‘clip’ through a character, wrecking the immersion of the scene and effect.

Check out our Batman: Arkham City PC trailer for a look at several of the impressive hardware-accelerated PhysX effects.

Beyond enhancing the believability and dynamism of a scene, the hardware-accelerated PhysX engine powers particle and destruction enhancements too. Generating a great deal of interest and discussion when revealed in our first PhysX video, the technology renders particles that react to forces realistically. For example, as part of a fog cloud they are pushed forward and sideways as a guard runs through, the momentum of the particles at the fore interacting with those even further forward to continue pushing particles outwards even after the guard stops moving.

Other uses of the particle system result in smoke and sparks being emitted from damaged machinery, small pieces of interactive debris, and larger piece of debris from destructible objects. With Hardware PhysX disabled in the game's Smelting Chamber, only a few particles can be seen high up toward the ceiling, each appearing in a prescribed, noticeable pattern, and with Hardware PhysX enabled particles shower the scene as one would expect. As Batman fights his foes beneath the smelter the anti-aliased, motion-blurred particles rain down, bouncing off characters accurately, dramatically adding to the scene’s immersion and the game’s overall sense of believability - gone are the days of fighting enemies in a static world oblivious to the actions occurring around it.

A badly-beaten Batman eats a face-full of ice. In the pictured scene, each ice crystal emits hundreds of ice particles, curtains and ropes flutter, and discarded pieces of paper whip into the air as Batman desperately tries to avoid death.

Further enhancing the sense of connectivity between scene elements are the aforementioned destruction enhancements. In the same smelting stage there is breakable glass that shatters realistically as you throw one of Joker’s many goons through it, its shards littering the scene afterwards, parting and being kicked up as the fight continues. Upstairs, away from the smelter, entrances to rooms are partially covered by strips of heavy, rubbery material; it too being manipulated by characters either walking through the doorways, or by being unceremoniously launched through by Batman.

In this one level alone gamers utilizing High Hardware Accelerated PhysX effects can interact with the aforementioned rubbery material, breakable glass, glass shards, office papers, bunting, and coal debris, and in the surrounding environment there are smelter sparks, electrical sparks, and welder sparks.

One of the most impressive uses of hardware PhysX is in a bank vault, each note being whipped into the air, dancing around the scene as a fight unfolds.

These are just a few of the many applications of PhysX in Batman: Arkham City, which together form the most impressive and extensive use of hardware accelerated physics ever seen (check out a detailed list of all the effects here). A true showcase of where the future lies.

Flip over to the next page to learn more about DirectX 11 effects, 3D Vision and fancy anti-aliasing modes.

Multi-View Soft Shadows (DirectX 11)

We often associate good in-game shadows as being crisp and accurately rendered, but in reality shadows are softer, non-uniform and the result of multiple light sources and their surroundings. In the real world our brains decode the lighter and darker segments of a shadow (penumbra and umbra, respectively), and the smooth transitions between them, allowing us to automatically determine a light source’s position and the size and orientation of objects being shadowed. And while no game can hope to account for every possible factor in determining the appearance of a real-world shadow for the foreseeable future, the latest titles offer ‘soft shadow’ approximations.

In Batman: Arkham City, DirectX 11 is leveraged to make these approximations more realistic using a technique known as Multi-View Soft Shadows (MVSS). To achieve this, MVSS generates the main character’s ‘hard shadow’ many times per light source, with these shadows then combined and averaged. With a new, averaged ‘shadow map,’ soft shadows are generated and displayed directly via a pixel shader. Through this process each pixel of each scene that is in shadow will have a stronger shadow intensity than a pixel that is in-shadow in only 50% of the scene’s shadow maps. In other words, every piece of each shadow can be hard or soft or any degree between based on the lighting and conditions in the scene.

Generated in real-time, every frame, every second, the effect can be demanding in the more complex scenes, hence why it is an optional, DirectX 11-powered effect.

Horizon-Based Ambient Occlusion (DirectX 11)

Also enabled by ‘DirectX 11 Features’ is Horizon-Based Ambient Occlusion (HBAO), a rendering technique developed by NVIDIA that dramatically improves the appearance of soft shadowing in relation to the player’s viewpoint, most evidently where two objects meet, such as a crate placed near a wall, with the shadow falling on the three surfaces.

Without HBAO, the small gap between the crate and wall wouldn’t be accurately shadowed as the engine would fail to account for light in the scene leaking between the two, which in reality would create a shadow. With HBAO, all such possibilities are calculated and the shadow generated, something that is best achieved in concert with the aforementioned MVSS. Furthermore, the finished result is then ever-so-slightly blurred to remove the unrealistic sharpness mentioned above.

Click for an animated example highlighting the loss of Multi View Soft Shadows and Horizon-Based Ambient Occlusion.

3D Vision

3D is hit and miss at the movies. Thankfully, this hit-miss ratio falls squarely in favor of the hits on the PC thanks to profiles that can be updated by NVIDIA, settings that can be tweaked by users, and bugs that can be fixed by developers, and you don’t have to pay extra for the implementation either. It should come as no surprise then, given the earlier info about PhysX, tessellation and general effects, that Batman: Arkham City is one of the most impressive 3D Vision titles to date.

<Edit: 3D Vision demonstration removed due to website shutting down>

For more 3D Vision screenshots head on over to 3DVisionLive.com.

Anti-Aliasing: FXAA, CSAA & MSAA

Anti-aliasing improves the visual fidelity of a scene by reducing the impact of unavoidable, unsightly jagged lines that go hand-in-hand with polygon-based game design. In Batman: Arkham City, developer Rocksteady allows gamers to choose between three techniques, each with their own quality settings, which we will now detail and compare.

First to appear in the configuration tool is Fast Approximate Anti-Aliasing (FXAA), a NVIDIA-developed anti-aliasing technique rapidly gaining traction in the games industry due to its high quality, low-cost results. Particularly powerful in engines using deferred shading, such as the Unreal Engine used by Batman: Arkham City, FXAA produces superior results compared to standard anti-aliasing methods for a far lower performance cost.

FXAA produces fantastic results on the transparent chain-link object, regardless of the quality chosen.

The differences between the various levels of FXAA anti-aliasing are more apparent in this second example, focusing on a solid piece of world geometry.

Next up is Multisample Anti-Aliasing (MSAA), the de facto anti-aliasing method in recent years. Very expensive to use, MSAA hurts performance and increases VRAM usage by a significant degree, though those with top-end GPUs may find 8x MSAA superior to FXAA High, regardless of the performance impact, due to the lack of an additional blur filter that is applied by FXAA.

MSAA is unable to anti-alias transparent textures such as the chain-links, and therefore fails to enhance the object’s fidelity in any way whatsoever.

MSAA is effective on geometry, however, as can readily be seen.

The final option is Coverage Sample Antialiasing (CSAA), an NVIDIA-developed anti-aliasing method first introduced with our 8-Series GPUs. By storing pixel coverage information in a very compact way, CSAA produces anti-aliased images that should rival the quality of the above 8x MSAA method whilst introducing only a minimal performance hit compared to 4x MSAA. In other words, less aliasing with less of a performance hit, though users seeking ultimate image quality may wish to reinvest those savings in 16xQ CSAA or 32x CSAA.

As with MSAA, CSAA is unable to anti-alias the chain link object.

16x and 16xQ CSAA produce inferior results compared to 8x MSAA, although at 32x the difference is negligible.

Our final side-by-side comparison shows that FXAA High and 8x MSAA are on par with each other, and that 32x CSAA is a ever-so-slightly behind. During gameplay the differences between the three are only truly perceptible when you come across the aforementioned chain-linked objects, at which point FXAA really shines. Of course, you could forcibly enable Transparency Multisampling and Supersampling through the NVIDIA Control Panel, though this would further increase the performance impact of MSAA and CSAA in comparison to FXAA High, which as you will see later is extremely efficient.

Given the comparisons above and our in-game experiences, we personally recommend FXAA High - as shown, it is the only anti-aliasing method capable of tackling the many chain-linked objects featured in the game, and though it introduces a slight screen-wide blur, reducing the game’s sharpness ever so slightly, we feel this is an acceptable trade-off to eliminate those extra transparency-based jaggies that MSAA and CSAA cannot touch.

With everything examined and explained click on over to the next page to check out performance using Arkham City’s built-in benchmarker.

Featuring so much advanced tech we were eager to discover how well Batman: Arkham City performed, and thanks to the inclusion of a repeatable, configurable benchmarking application we were able to capture accurate information regarding the performance of each and every graphics card in NVIDIA’s line-up. Through this testing, we were able to ascertain how much of an impact the various anti-aliasing modes, graphics effects and advanced features have, allowing us to recommend the best settings for your particular graphics card and to help you configure your game for the best possible experience.

DirectX 9 Performance

The 8800 GT and 9800 GT: one and the same, and still the most popular graphics card amongst Steam’s many millions of users. Released several years ago, the two cards have hung onto the coat tails of newer GPUs, somehow producing playable results in the majority of recent releases.

Listed in Arkham City’s Minimum System Requirements sheet as the oldest graphics cards able to give you any kind of playable experience, let’s discover how they perform:

On our i7 2600K test system the venerable GPUs surprised us once more by breezing past 60 frames per second at 1920x1080 using the highest detail level. Not being DirectX 11 graphics cards, MVSS, HBAO and Tessellation are all off-limits, and lacking the number of CUDA cores of the latest GPUs, PhysX isn't a possibility either without sacrificing resolution, detail levels and the silky smooth frame rate.

DirectX 11 Performance

Batman: Arkham City on the PC is meant to be played with all the bells and whistles enabled. To do so requires a DirectX 11-compatible graphics card, such as the latest 500-Series NVIDIA GPUs.

In the following section we’ll test each of these cards with progressively better settings to determine what kind of GPU you’ll require for a given gameplay experience. Each test was conducted using a stock-clocked Intel i7-2600K, a P67 motherboard, and 8GB of DDR3 RAM. The Very High detail preset and DirectX 11 effects enabled were enabled, in addition to any configuration options listed on the charts.

Anti-Aliasing

At this baseline level the GeForce GTX 550 Ti comfortably handles 1920x1080 and the other cards are barely taxed. Let's up the ante by enabling Anti-Aliasing.

With 4xMSAA enabled the GTX 550 Ti is unable to replicate its impressive level of performance from the first test, though it does still produce a playable result at the lowest resolution. The GTX 560 is the first card to break 40 frames per second at 1920x1080, and the GTX 570 the first at 2560x1600.

8xMSAA has a massive impact on performance across the board - the GTX 550 Ti goes sub-30 FPS and is unable to complete the final test; the GTX 560 and GTX 560 Ti are only able to stay above 40 FPS at 1600x900; the GTX 570 stays just above 40 FPS at 1920x1080, where previously it was at 72 FPS; and the GTX 580 went as low as 29 FPS at 2560x1600. Only the GTX 590 remained playable at max res, producing a result of 43.6 FPS.

32xCSAA is even more demanding than 8xMSAA, lowering results by up to 9 frames per second across the board. This forces the GTX 560 below 40 FPS at any resolution, the GTX 570 below 40 FPS at 1920x1080, and the GTX 590 below 40 FPS at 2560x1600.

In stark contrast, FXAA High has a minimal impact on frame rates and produces in-game results similar to that of 8xMSAA, whilst also anti-aliasing transparencies. Using this AA technique the GTX 550 Ti and GTX 560 run well above 40 FPS at 1920x1080, and at 2560x1600 every other GPU is suitable for use. The slowest, the GTX 560 Ti, runs at a respectable 42.8 FPS.

Our first set of results reveal that a GeForce GTX 550 Ti can play Batman: Arkham City with a level of fidelity far superior to that of the console releases, and that FXAA High is a far more efficient anti-aliasing technique compared to MSAA and CSAA.

Normal Tessellation & PhysX

Due to MSAA and CSAA's severe impact on performance we removed the anti-aliasing techniques from our tests and continued only with FXAA High. The next batch of tests reveal the performance of the lowest level of tessellation, 'Normal,' and the impact of PhysX when enabled alongside it.

The enabling of 'Normal' tessellation has a nominal impact on frame rates across the board compared to our previous FXAA High, tessellation disabled results; the general impact being a few frames per second. This minute reduction has no impact on the overall result, meaning the GTX 550 Ti is still well and truly playable at 1920x1080.

With the lowest level of PhysX enabled the picture changes significantly, but not the overall result, meaning the GTX 560 and 560 Ti still run at 40 FPS and above at 1920x1080 and the GTX 570, 580 and 590 do the same at 2560x1600. The only exception is the GTX 550 Ti, which now falls below the 40 FPS sweet spot at 1600x900 and 1920x1080.

With PhysX High enabled frame rates dropped once more, and the overall result changed slightly - the GTX 560 fell below 40 FPS at 1920x1080 by 0.3 FPS, though that is well within accepted variance for benchmarks, and the GTX 570 fell below 40 FPS at 2560x1600, leaving only the GTX 580 and 590 above the sweet spot at the max resolution.

With our second set of tests we have discovered that Normal tessellation makes very little difference to performance, unlike PhysX, which dramatically reduces frame rates. However, the mid-range and high-end 500-Series GPUs had a significant enough performance margin to prevent these demanding effects from pushing frame rates below our 40 FPS sweet spot.

High Tessellation & PhysX

For our final set of tests we enabled 'High' tessellation and PhysX, pushing our graphics cards to the limit.

Going from Normal tessellation to High tessellation results in the loss of a few frames per second across the board.

Because the difference in performance between Normal and High tessellation is so slight, only the GTX 570 result changes, it now being incapable of 40 FPS at 2560x1600.

Our most demanding test changes the landscape slightly - the GTX 560 now clearly falls outside of the 40 FPS sweet spot at 1920x1080, and the GTX 560 Ti just inside; the GTX 570 becomes our clear 1920x1080 winner; and the GTX 580 falls just below 40 FPS at 2560x1080.

Our final set of tests show that the performance difference between Normal and High tessellation is only a few frames per second, and that the performance difference between PhysX Normal and High, when every other setting is enabled, is up to 13 frames per second extra.

To more clearly demonstrate the performance difference between the two PhysX options we've compiled one final chart:

All 500-Series graphics cards can max out every game setting in conjunction with FXAA High, but only a few can do so at over 40 frames per second.

Summary: Optimal Playable Settings

GeForce GTX 580

The only card capable of running Batman: Arkham City at over 40 frames per second at our max resolution, using the max possible settings, High tessellation and High PhysX.

GeForce GTX 580

The GTX 580 is more than capable of playing Arkham City at 1920x1080 and was just 0.4 frames per second shy of 40 at 2560x1600, so with the tiniest of overclocks it would easily enter the sweet spot and give you a flawless gameplay experience at our maximum tested resolution.

GeForce GTX 570

The GTX 570 was the first card to comfortably handle Arkham City at 1920x1080 with PhysX and tessellation set to High. Recommended for users of ~23" monitors.

GeForce GTX 560 Ti

The GTX 560 Ti sits in the sweet spot at 1920x1080 by just 0.6 frames per second when using High tessellation and PhysX. Dropping down to Normal PhysX would give you an extra 5.8 frames per second.

GeForce GTX 560

At 1920x1080 we were only able to use Normal PhysX in conjunction with High tessellation to remain within the 40 frames per second sweet spot, though at 1600x900 we did record a result of 41.7 frames per second using both High PhysX and tessellation, so if desperately want the extra PhysX effects without sacrificing your frame rate, reducing the resolution is the way to go.

GeForce GTX 550 Ti

For a budget card the GTX 550 Ti performs amazingly well, hanging on in there with the costlier mid-range cards until we added PhysX, the most demanding feature in Batman: Arkham City. Paired with a similarly-priced processor you’ll receive a fantastic experience, superior to that offered by the consoles, albeit without realistic PhysX niceties.

Using A Second Graphics Card As A Dedicated PhysX Processor

Do you have an old CUDA-enabled graphics card lying around somewhere gathering dust? What if we told you that you can use that card to accelerate your frame rate in Batman: Arkham City when utilizing the PhysX effects?

All you have to do is plug a GeForce 8, 9, 200, 400 or 500 Series GPU into a spare PCI-Express slot on your motherboard, attach any required power cables, switch the PC back on, and then set up your NVIDIA Control Panel as shown below, ignoring the references to SLI that won’t appear unless you’re inserting a third card alongside an existing SLI configuration.

To ascertain the performance improvement from a second graphics card set as a dedicated PhysX processing unit, we tested a GeForce GTX 560 Ti at the more demanding 1920x1200 resolution, denoted as ‘None’ in the chart below, and then re-ran our benchmarks using a number of popular NVIDIA GeForce GPUs in the required configuration.

By repurposing a piece of five-year-old kit gathering dust on a shelf we’ve boosted our Batman: Arkham City frame rates by 11.56%, pushing the GTX 560 Ti into the forty frames per second sweet spot when using every single effect and enhancement (if you don’t already own a 8800 GT or 9800 GT, they’re cheap as chips on eBay). Another popular, ageing graphics card, the GeForce GTX 260, improved frame rates by 17.55%, and a second GTX 560 improved frame rates by 23.71%.

This performance improvement scales somewhat with your processor's power, so those with older CPUs will receive less of a benefit from the secondary card, though it should still make a noticeable impact on the overall frame rate. In the end, any improvement is an improvement worth having, so hold onto your old NVIDIA tech as it will come in handy in similar situations in the future.