Summary: Mirror's Edge is the first AAA game to support PhysX natively in the box. In this article we take a look at the game's new PhysX effects, evaluating their impact graphically and on 3D performance. Is Mirror's Edge finally the killer app PhysX has sorely needed? Judge for yourself after reading today's article!
Mirror’s Edge is the first 2009 title to support the technology. Mirror’s Edge also happens to be the first AAA title to support PhysX out-of-the-box: PhysX is an adjustable setting that can be toggled on and off from right within the game’s graphics menu, regardless if you have a GeForce GPU or not. Obviously if you don’t have GeForce 8 or better card installed, PhysX will run on your PCs CPU instead of the GPU. Or if you happen to have an AGEIA PhysX PPU card, you can run Mirror’s Edge on that as well.
PhysX enhancements in Mirror’s Edge
So what enhancements does PhysX bring to Mirror’s Edge? Quite a few. The most obvious addition to the game is persistent shattered glass.
In this second sequence of screenshots you can see the results when a team of SWAT officers takes out a glass display case and more windows in this room:
Besides adding curtains to windows for the PhysX version of Mirror’s Edge, DICE has also added cloth tarps in select areas of levels as well. These tarps flap in the wind, and respond accordingly when shot:
With PhysX disabled, these tarps aren’t even present in the game:
The final PhysX effect we captured screenshots of is the helicopter kicking up debris in the prologue of the game. As you can see in the shots, with PhysX enabled, newspapers and other objects on the rooftop fly across the screen when the helicopter descends. With PhysX off, these objects aren’t present.
Besides these aforementioned effects, NVIDIA and DICE also use PhysX to provide volumetric smoke and fog but unfortunately we didn’t snag any good shots of that. The best way to see these PhysX effects in action is still the updated Mirror’s Edge PhysX trailer NVIDIA provided us back in December. The video provides a side-by-side comparison showing Mirror’s Edge running with PhysX, versus without:
Mirror’s Edge PhysX Impressions
Overall, the added PhysX effects add an additional layer of polish to the game, although we wouldn’t by any means label them as game changers. Unlike PhysX games like Warmonger or Cell Factor, the added physics elements in Mirror’s Edge don’t affect gameplay – for instance there are rumors floating around that shattering glass in Mirror’s Edge with PhysX can cause damage to your character, but those rumors aren’t true. We tested this out by standing right next to a window multiple times as it was shattered and didn’t take any damage.
Intel Core i7-965 Extreme Edition
EVGA X58 SLI
3GB Qimonda DDR3-1066
NVIDIA GeForce GTX 260 216 Shaders
NVIDIA GeForce 9800 GTX+
NVIDIA GeForce 8800 GT
NVIDIA GeForce 9600 GT
ATI Radeon HD 4830 512MB
ATI Radeon HD 4850 512MB
ATI Radeon HD 4870 1GB
BFG PhysX PPU 128MB PCI
PhysX Pack 8.09.04
300GB Western Digital Caviar SE
Windows Vista Ultimate 64-bit w/Service Pack 1
Mirror’s Edge with PhysX Patch and maximum graphics settings
Since Mirror’s Edge lacks a built-in utility for benchmarking, we loaded up FRAPS to record frame rate. Our test sequence comes from checkpoint C of the flight map, and is represented in many of the screenshots from the previous page. At this particular checkpoint a SWAT officer mounted in a Blackhawk helicopter repeatedly fires at you while running through a building. Your character runs out the building, jumps over the edge, and slides down the side to the rooftop of another nearby highrise office building. It’s a pretty action-packed sequence as the chopper is constantly firing on you, sending glass shards everywhere.
In order to test the performance hit of turning on PhysX, we’ve rounded up three relatively affordable GeForce cards running them with PhysX enabled on the GPU, versus turning the feature off completely:
Mirror’s Edge – Direct3D
As you can see, turning on GPU-based PhysX had a profound impact on performance. The GeForce GTX 260 saw its frame rate drop by nearly half at 1920x1200, falling 40%. The 9800 GTX+ and 8800 GT saw slightly lower hits of 35% and 33% respectively, but the performance drop was still pretty significant. In fact, enabling PhysX has such a large hit on performance, the GTX 260 and 9800 GTX+ perform awfully close to one another at 1600x1200. Only under the greater graphics demand of 1920x1200 does the GTX 260 begin to pull away from the 9800 GTX+.
Mirror’s Edge – Direct3D
Without PhysX enabled, ATI’s Radeon 4800 series takes a backseat to GeForce in Mirror’s Edge. The 4830 lost against its nearest competitor, the 8800 GT, while the 4850 and 4870 were also outperformed by NVIDIA’s equivalent GeForce products, the 9800 GTX+ and GeForce GTX 260. The margins weren’t a complete blowout though. At 1920x1200 the Radeon 4870 and 4830 fell just 5% behind the GTX 260 and 8800 GT respectively, while the 4850 finished 5.5 fps (10%) behind the 9800 GTX+.
As you’d expect, running PhysX on the CPU severely hampers performance:
Mirror’s Edge – Direct3D
In our testing, Mirror’s Edge performance dropped by a factor of roughly 2.5X when PhysX is run on the CPU versus the GPU. As you can imagine, this results in performance that’s completely unplayable, even on a Core i7-965 CPU.
What happened when we plugged in our trusty PCI BFG PhysX PPU card? Despite its age, the PPU performs quite well in Mirror’s Edge:
Mirror’s Edge – Direct3D
The Radeon 4800 GPUs saw a nice performance boost with the PPU handling PhysX effects, but still can’t catch up to the GeForce GPUs when they’re also paired up with BFG’s PPU card. The Radeon 4870+PPU combo finished behind the GeForce GTX 260+PPU combo by 7%. Meanwhile, the Radeon 4850+PPU setup ran 13% slower than the 9800 GTX+ PPU rig. Fortunately for ATI the margins are slimmer at 1600x1200, where the PhysX effects themselves are more of a bottleneck.
Mirror’s Edge – Direct3D
First off, as we’ve seen in previous PhysX performance articles, the GeForce 9600 GT delivers the best PhysX performance for the dollar among GPUs. PhysX performance was basically on par with the vastly more powerful 9800 GTX+ when both were paired with the GeForce GTX 260 handling graphics.
How effective this eye candy is, and whether or not the same or similar effects could also be handled by the CPU (or the GPU using Havok) has been a source of much public debate. Like Ghost Recon: Advanced Warfighter (GRAW), Mirror’s Edge is probably one of those games that could fall into this category.
Now sure, the game looks best when played with PhysX enabled, and there’s no disputing that fact. Going back and forth between PhysX on and off as we did you really get a sense of how stale and boring the game environment is once PhysX is disabled: the game world really comes alive and looks more like a real city with PhysX enabled.
At the same time however, critics will point out that some of the PhysX additions integrated into Mirror’s Edge PC have been handled successfully by the CPU in other PC games in the past: Mirror’s Edge isn’t the first game to feature persistent objects or volumetric smoke/fog. NVIDIA would then likely argue back that previous games didn’t feature physically correct volumetric smoke; the cloth effects with curtains, tarps, and scaffolding that rip realistically in Mirror’s Edge are also impressive.
Basically, Mirror’s Edge is more of an evolutionary progression rather than a revolutionary leap when it comes to in-game physics. Consider it a step in the right direction, but it’s nowhere near the level of a game like Warmonger or Cell Factor.
Looking at the actual benchmarks themselves, NVIDIA’s GeForce GPUs currently have the edge in Mirror’s Edge at this point. Whether you’re gaming with PhysX on or off, and even with an AGEIA PPU card in place, each of the GeForce boards we tested still outperformed their nearest rival from ATI.
Also embarrassing for ATI is the fact that the Radeon 4870 X2 doesn’t scale properly in the game – after spending the past year telling us that their CrossFire scaling performance has improved, they’ve stumbled with the first major PC game release of 2009. This is a major issue ATI needs to address if they wish to restore confidence after the debacle that was the summer of 2007 when many major titles (including BioShock) were released back-to-back without CrossFire profiles.
With F.E.A.R. 2 shipping to stores next week, we’ll be watching closely to see how the 4870 X2 scales with this game.
It will be interesting to see how history judges Mirror’s Edge a few years from now though. Hopefully you saw last week’s review of Mirror’s Edge PC. The game scored a 76% in the review. One of Tom’s biggest gripes was the game’s combat system. After playing the game myself, I completely agree with him. Considering their background with the Battlefield series, DICE’s gun combat implementation in Mirror’s Edge is abysmal. As a result, guns really do play a very minor role in this game. Also, like recent EA Games, Mirror’s Edge features the same draconian SecuROM DRM scheme used in games like Spore and Crysis Warhead.
Four or five years from now, Mirror’s Edge PC will probably be remembered more for issues like these than for PhysX. We wouldn’t be surprised if only the savviest hardware enthusiast remembers that this was the first major game title to ship with built-in PhysX support. That’s both a testament to how smoothly PhysX has been integrated into the game, yet could also be a hindrance when it comes to selling PhysX-compliant hardware. This isn’t a GL Quake moment, where id’s shooter helped 3dfx sell 3D video cards, or a Wing Commander moment, where the game’s voice support helped Creative sell Sound Blaster audio cards.
So here we are, February 2009, still waiting for PhysX’ first killer app…
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