PhysX Performance Update: City of Villains
by Ryan Smith on September 7, 2006 6:00 AM EST- Posted in
- GPUs
Final Words
While we still think that on paper, the AGEIA's PhysX technology has promise, we find ourselves in a situation similar to where we were a few months ago with Ghost Recon and the City of Villains beta. On the positive side, AGEIA and Cryptic have fixed many of our earlier complaints about using PhysX hardware acceleration under City of Villains. The game no longer stutters, and installing a PhysX card doesn't immediately result in a drop in performance (though this has much to do with the new way of adjusting physics settings and other optimizations Cryptic has made in how the game handles large quantities of debris).
However, what AGEIA has failed to fix, and what ultimately ends up counting the most, is value. There's no question that a PhysX card will give better performance in City of Villains at the highest settings, and at times that difference can be pretty sizable. But as we found out, using a slightly lower quality physics mode will result in graphics similar to the highest mode where the PhysX card shines, but at performance levels nearly equal to the PhysX card just by using a dual-core CPU. When we're talking about adding a $250 PPU to a system that's already using a $1000 CPU and a $500 GPU, the PhysX card is a sensible way to boost performance by a good measure without spending all that much more. Under a tighter budget, that's a much harder thing to recommend.
For someone currently using a single-core CPU and working with a limited budget, an upgrade to a dual-core CPU is going to be superior to adding the PhysX card in City of Villains, and it's going to be much more useful in games and applications where the PhysX card can't be used. Similarly, someone with a slower dual-core CPU may not see gains as great going to a faster CPU as they would with a PhysX card, but unless the extra eye-candy and a few frames is what you desire, the faster CPU will still be more useful overall. Ultimately, since City of Villains is CPU limited, the PhysX card is only the best upgrade when a system's CPU performance can't be improved much; otherwise, the effect of the CPU holding back performance is just too great to ignore.
Eventually, we still must question the usefulness of a product like the PhysX card on a game like City of Villains. Physics processing is an embarrassingly parallel problem, the kind of problem that the hardware industry has gotten extremely good at solving first with video and GPUs, and now physics and PPUs. But this technology must be put to a better use if AGEIA wants to drive more adoption and influence an era of video games that can make a massive jump in the number of physics interactions used. Adding more particles to games like City of Villains -- and then only to certain segments of the game -- is really demeaning for the hardware; it's not changing gameplay and it's not something at which a PPU can universally excel versus other options such as additional CPU cores, even given the sheer advantage of hardware optimized for these calculations over a general-purpose processor.
We still believe that PPUs can influence and improve gaming, but it must be done in ways that make sense in improving gameplay, or at the very least improve things in ways not related to gameplay such that there's a clear benefit over the alternatives. City of Villains and similar games won't be able to sell the PPU (with the exceptions of wealthy die hard fans); that will have to come in the following years as games like CellFactor take root which implement the PPU in a more pervasive manner to create an undeniably more immersive experience.
If AGEIA could even promise a consistent 25% performance boost over software mode in several games, more people would be interested in the technology. The problem is, many games are completely GPU limited, so faster physics processing doesn't necessarily help. What we end up with is the classic chicken vs. egg problem: without a large installed base of PPUs, how many developers will even bother to try and take advantage of the technology, and without software that takes advantage of the technology, who will want to buy the hardware? ATI and NVIDIA are also working on trying to accelerate physics with their GPUs, and every gamer will already have that technology available. GPU-based physics calculations might not be a good solution in games that are already GPU limited, but faster processors and PPUs won't help such games either.
While we still think that on paper, the AGEIA's PhysX technology has promise, we find ourselves in a situation similar to where we were a few months ago with Ghost Recon and the City of Villains beta. On the positive side, AGEIA and Cryptic have fixed many of our earlier complaints about using PhysX hardware acceleration under City of Villains. The game no longer stutters, and installing a PhysX card doesn't immediately result in a drop in performance (though this has much to do with the new way of adjusting physics settings and other optimizations Cryptic has made in how the game handles large quantities of debris).
However, what AGEIA has failed to fix, and what ultimately ends up counting the most, is value. There's no question that a PhysX card will give better performance in City of Villains at the highest settings, and at times that difference can be pretty sizable. But as we found out, using a slightly lower quality physics mode will result in graphics similar to the highest mode where the PhysX card shines, but at performance levels nearly equal to the PhysX card just by using a dual-core CPU. When we're talking about adding a $250 PPU to a system that's already using a $1000 CPU and a $500 GPU, the PhysX card is a sensible way to boost performance by a good measure without spending all that much more. Under a tighter budget, that's a much harder thing to recommend.
For someone currently using a single-core CPU and working with a limited budget, an upgrade to a dual-core CPU is going to be superior to adding the PhysX card in City of Villains, and it's going to be much more useful in games and applications where the PhysX card can't be used. Similarly, someone with a slower dual-core CPU may not see gains as great going to a faster CPU as they would with a PhysX card, but unless the extra eye-candy and a few frames is what you desire, the faster CPU will still be more useful overall. Ultimately, since City of Villains is CPU limited, the PhysX card is only the best upgrade when a system's CPU performance can't be improved much; otherwise, the effect of the CPU holding back performance is just too great to ignore.
Eventually, we still must question the usefulness of a product like the PhysX card on a game like City of Villains. Physics processing is an embarrassingly parallel problem, the kind of problem that the hardware industry has gotten extremely good at solving first with video and GPUs, and now physics and PPUs. But this technology must be put to a better use if AGEIA wants to drive more adoption and influence an era of video games that can make a massive jump in the number of physics interactions used. Adding more particles to games like City of Villains -- and then only to certain segments of the game -- is really demeaning for the hardware; it's not changing gameplay and it's not something at which a PPU can universally excel versus other options such as additional CPU cores, even given the sheer advantage of hardware optimized for these calculations over a general-purpose processor.
We still believe that PPUs can influence and improve gaming, but it must be done in ways that make sense in improving gameplay, or at the very least improve things in ways not related to gameplay such that there's a clear benefit over the alternatives. City of Villains and similar games won't be able to sell the PPU (with the exceptions of wealthy die hard fans); that will have to come in the following years as games like CellFactor take root which implement the PPU in a more pervasive manner to create an undeniably more immersive experience.
If AGEIA could even promise a consistent 25% performance boost over software mode in several games, more people would be interested in the technology. The problem is, many games are completely GPU limited, so faster physics processing doesn't necessarily help. What we end up with is the classic chicken vs. egg problem: without a large installed base of PPUs, how many developers will even bother to try and take advantage of the technology, and without software that takes advantage of the technology, who will want to buy the hardware? ATI and NVIDIA are also working on trying to accelerate physics with their GPUs, and every gamer will already have that technology available. GPU-based physics calculations might not be a good solution in games that are already GPU limited, but faster processors and PPUs won't help such games either.
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shank15217 - Saturday, September 16, 2006 - link
All this review shows is how good the AGEIA software engine is capable of using a second core to it's full advantage. Infact their goals are slightly two sided. Its true the hardware is probably a magnitude faster than cpus but cpus are reaching 4 core and beyond with shared caches and very wide busses. Unless AGEIA puts their hardware implementation on a PCI Express / HTX slot its not gonna outrun even a 4 core core 2 duo or an athlon 64 for that matter.Vergil - Monday, September 11, 2006 - link
Ageia's PPU should be integrated with the motherboard to for maximum results ladies and gentzCan you imagine having the raw horsepower of a motherboard with a local GPU thats powerful as a 7800 GTX? Local components work better with any CPU(meaning have a better data transfer/flow rate) than any serial bus. Motherboard bus speeds(PCI/AGP/PCIe) limit the performance of most video & other cards(even the high end ones) to some degree. However, PCI-e is the next best thing without having it on the die with the CPU. But with chipsets that help with physics, it has to catch it BEFORE it hits the CPU, which is why there is a major performance hits to City of Villians. The CPU has to collect all of the data before everything else gets it providing thats its not integrated. Then it has th elaborious task of dealing with data it isnt prepared to use.
soulshagga - Saturday, September 9, 2006 - link
The author obviously hasn't written a physics engine before.The problem is n! in complexity -- the reason being is each entity interacts with each other. You can't just blindly update n entities independently of each other (consider collision detection for instance).
I won't elaborate here because it is beyond the scope of this article, not to mention these forum posts, but just think about what would happen if you just blindly update the physical attributes of n entities... you would lose information. If you don't get what I'm saying, don't worry about it -- just take my word for it. :)
Please, don't make bold statements like that if you are unsure.
Thanks.
ojingoh - Thursday, September 7, 2006 - link
sorry for the confusion -- i see you in fact did run the game unacellerated, thanks for thatojingoh - Thursday, September 7, 2006 - link
what i meant by the minimum physics -- this card does physical calculations, not just particles. things like collisions and deformations etc.ojingoh - Thursday, September 7, 2006 - link
i have an issue with your review. your testing doesnt include screenshots of the things tested.please explain "slightly lower quality physics mode" -- what setting was this? 75%? 50%? without screenshots it's hard to identify what you claim. the slider states "up to" implying that some frames will have the maximum but some have far less. is it hard to tell the diffrence between 500 and 1000 particles? what would be a reasonable number of particles?
also you exclude any test showing what happens when you have the card installed but run the game at minimum phisics, i think in cov it's 100 particles (idk if this is the case, this is also not tested.)
Regs - Thursday, September 7, 2006 - link
Dual core actually helps physics processing? I guess this is only in games that support dual core.PrinceGaz - Friday, September 8, 2006 - link
I imagine that most games which have support for offloading work to the PhysX card will also support offloading the same work to a seperate "software-physics" thread. If they've already made the effort to seperate the physics work from the main application so it can be sent to the PhysX card, it should be trivial to run that work in a second (or multiple) threads. Therefore games that make use of the PhysX card will most likely also be able to use a dual-core processor to good effect, as is the case with CoV.Calin - Friday, September 8, 2006 - link
I assume more games support dual cores than PPU right now (and the trend probably favours the dual cores rather than the PPU)Anyway, a dual core will help with short processor-intensive (even if very short) tasks that appear "out of the blue" - antivirus, some operating system tasks/schedules/other activities
Missing Ghost - Thursday, September 7, 2006 - link
As soon as there is a PCIe 1x/4x version available, I will buy it.