Ageis PhysX...The true future of PC Physics? Serious Doubts...
I have read all your posts with great interest, I feel that some very good points are being made, so here's my 2 cents worth ;-)
I believe the 'IDEA' of having a dedicated PPU in your increasingly expensive monster rig is highly appealing, even intoxicating and I believe this 'IDEA' coupled with some clever marketing will ensure a good number of highly overpriced, or at least expensive, sales of this mystical technology in it's current (ineficient) form.
For some, the fact that it's expensive and also holds such high promises will ensure it's place as a 'Must have' component for the legions of early adopters. The brilliant idea of launching them through Alienware, Falcon Northwest and the top of the line Dell XPS600 systems was a stroke of marketing genius as this adds to the allure of owning one when they finally launch to the retail market...If it's good enough for a system most of us can never afford but covet none the less it's damn well good enough for my 'monster RIG'. This arrangement will allow the almost guaranteed sales of the first wave of cards on the market. I have noticed that some UK online retailers have already started taking pre-launch orders for the £218 OEM 128MB version I just have to woner how many of these pre-orders have actually been sold?
The concept of a dedicated PPU is quite simply phenominal, We spend plenty of money upgrading our GPU's, CPU's and quite recently Creative have brought us the first true APU (X-Fi series) that it makes sense for there to be a dedicated PPU and berhaps even an AiPU to follow.
The question is, will these products actually benefit us to the value of their cost?
I would say that a GPU, or in fact up to 4 GPU's running over PCIe x32 (2xPCIe x16 channels) become increasingly less value for money the more GPU's added to the equation. i.e. a 7900GTX 512MB at £440 is great bang for the buck compared to Quad SLI 7900GTX 512MB at over £1000. The framerates in the Quad machine are not 4x the single GPU. Perhaps this is where GPU's could trully be considered worthy of nVidia or ATI's Physics SLI load balancing concept. SLI GPU's are not working flat out 100% of the time...Due to the extremely high bandwidth of Dual PCIe x16 ports there should be a reasonable amount of bandwidth to spare on Physics calculations, perhaps more if Dual PCIe x32 (or even quad x16) Motherboards inevitably turn up. I am not saying that GPU's are more efficient than a DEDICATED and designed for PPU, just that if ATI and nVidia decided the market showed enough potential, they could simply 'design in' or add PPU functionality to their GPU cores or GFX cards. This would allow them to tap into the extra bandwidth PCIe x16 affords.
The Ageis PhysX PPU in it's current form runs over the PCI bus, a comparitively Narrow bandwicth bus, and MUST communicate with the GPU in order for it to render the extra particles and objects in any scene. This in my mind would create a Bottleneck as it would only be able to communicate at the bandwidth and speed afforded by the Narrow bandwidth and slower PCI bus. The slowest path governs the speed of even the fastest...This would mean that adding a dedicated PPU, even a very fast and efficient one, would be severely limited by the bus it was running over. This phenomenon is displayed in all the real world benchmarks I have seen of the Ageis PhysX PPU to date, The framerates actually DROP when the PPU is enabled.
To counter this, I believe, Ageis through ASUS, BFG and any other manufacturing partner they sign up with will have to release products designed for the PCIe bus. I believe this is what Ageis knows as the early manufacturing samples were able to be installed in the PCI bus as well as the PCIe bus (although not at the same time ;-) ). I believe the PCI bus was chosen for launch due to the very high installed user base of PCI motherboards, every standard PC I know of that would want a PPU in their system. I belive this is a mistake, as the users most likely to purchase this part in the 'Premium price' period would likely have PCIe in their system, or at least would be willing to shell out an extra £50-£140 for the privelage. Although I could be completely wrong in this as it may allow for some 'Double Selling' as when they release the new and improved PCIe version, the early adopters will be forced to buy into it again at a premium price.
This leads me neatly onto the price. I understand that Ageis, quite rightly, are handing out the PhysX SDK freely, this is to allow maximum compatibilty and support in the shortest period of time. This does however mean that the end user, who purchases the card in the beginning will have to pay the full price for the card...£218 for the 128MB OEM version. As time goes by and more units are sold, the installed userbase of the PPU will grow and the balance will shift, Ageis will be able to start charging the developers to use their 'must have' Hardware Physics support in their games/software and this will subsidise the cost of the card to the end user, therefore making them even more affordable to the masses and therefore making it a much more 'Must Have' for the developers. This will take several generations of the PPU before we feel the full impact of this I believe.
If ATI and nVidia are smart, they can capitalise on their high installed initial userbase and properly market the idea of Hardware physics for free with their SLI physics, they may be able to throw a spanner in the works for Agies while they attempt to attain market share. This may benefit the consumer, although it may also knock Agies out of the running depending on how effective ATI and nVidias driver based solution first appears. It could also prompt a swift buy out from either ATI or nVidia like nvidia did with 3DFX.
Using the CPU for Physics, even on a multicore CPU, in my opinion is not the way forward. The CPU is not designed for physics calculations, and from what I hear they are not (comparitively) very efficient at performing these calculations. A dedicated solution will always be better in the long run. This will free up the CPU to run the OS and also for Ai calculations and well as antivirus, firewall, background applications and generally keeping the entire system secure and stable. Multicore will be a blessing for PC's and consoles, but not for such a specific and difficult (for a CPU) task.
"Deep breath" ;-)
So there you have it, My thoughts on the PPU situation as it stands now and into the future. Right now I will not be buying into the dream, but simply keeping the dream alive by closely watching how it develops until such a time as I believe the 'Right Time' comes. £218 for an unproven, generally unsupported, and possibly seriously flawed incarnation of the PPU dream is not in my opinion The Right Time, Yet ;-)