Just like with the PS2's Emotion Engine, with its missing L2 cache, the Cell is designed for a type of game programming that accounts for a minor percentage of processing time.
Sony's CPU is ideal for an environment where 12.5% of the work is general-purpose computing and 87.5% of the work is DSP calculations. That sort of mix makes sense for video playback or networked waveform analysis, but not for games. In fact, when analyzing real games one finds almost the opposite distribution of general purpose computing and DSP calculation requirements. A relatively small percentage of instructions are actually floating point. Of those instructions which are floating-point,...
Based on measurements of running next generation games, only ~10-30% of the instructions executed are floating point. The remainders of the instructions are load, store, integer, branch, etc. Even fewer of the instructions executed are streaming floating point—probably ~5-10%. Cell is optimized for streaming floating-point, with 87.5% of its cores good for streaming floating-point and nothing else.
Xbox 360's CPUs has vector processing power on each CPU core. Each Xbox 360 core has 128 vector registers per hardware thread, with a dot product instruction, and a shared 1-MB L2 cache. The Cell processor's vector processing power is mostly on the seven DSPs.
Dot products are critical to games because they are used in 3D math to calculate vector lengths, projections, transformations, and more. The Xbox 360 CPU has a dot product instruction, where other CPUs such as Cell must emulate dot product using multiple instructions.
Cell's streaming floating-point work is done on its seven DSP processors. Since geometry processing is moved to the GPU, the need for streaming floating-point work and other DSP style programming in games has dropped dramatically.
The Xbox 360 processor was designed to give game developers the power that they actually need, in an easy to use form. The Cell processor has impressive streaming floating-point power that is of limited use for games.
The majority of game code is a mixture of integer, floating-point, and vector math, with lots of branches and random memory accesses. This code is best handled by a general purpose CPU with a cache, branch predictor, and vector unit.
The Cell's seven DSPs (what Sony calls SPEs) have no cache, no direct access to memory, no branch predictor, and a different instruction set from the PS3's main CPU. They are not designed for or efficient at general purpose computing. DSPs are not appropriate for game programming.
More Detail on the Xbox 360 GPU
ATI has been working on the Xbox 360 GPU for approximately two years, and it has been developed independently of any PC GPU. So despite what you may have heard elsewhere, the Xbox 360 GPU is not based on ATI's R5xx architecture.
Unlike any of their current-gen desktop GPUs, the 360 GPU supports FP32 from start to finish (as opposed to the current FP24 spec that ATI has implemented). Full FP32 support puts this aspect of the 360 GPU on par...
ATI did clarify that although Microsoft isn't targetting 1080p (1920 x 1080) as a resolution for games, their GPU would be able to handle the resolution with 4X AA enabled at no performance penalty.
click my Factual posts as Offensive...I would have to say NJ. He has done it before. He has been busted many times with multi accounts. But I'm going to make you work boy. lol....You ready? The truth to sony fans is like kryptonite is to super man. Only yall are little girlies. Can't handle the truth huh....well there is a lot more where that came from girls.
ATI has been working on the Xbox 360 GPU for approximately two years, and it has been developed independently of any PC GPU. So despite what you may have heard elsewhere, the Xbox 360 GPU is not based on ATI's R5xx architecture.
Unlike any of their current-gen desktop GPUs, the 360 GPU supports FP32 from start to finish (as opposed to the current FP24 spec that ATI has implemented). Full FP32 support puts this aspect of the 360 GPU on par with NVIDIA's RSX.
ATI did clarify that although Microsoft isn't targetting 1080p (1920 x 1080) as a resolution for games, their GPU would be able to handle the resolution with 4X AA enabled at no performance penalty.
Microsoft said its Xbox 360 game console sales will total as many as 15 million by the end of its fiscal 2007, which ends June 30 of next year.
The company expects to have shipped more than 10 million Xbox 360 consoles by the end of this year. By the end of June, 2007, the company expects its sales to total between 13 million and 15 million units since the launch.
Its forecast for its fiscal 2007 is to ship between 8 million and 10 million Xbox 360 game machines....
There was no Sony conference in Leipzig this week, and the only announcement to emerge was a desultory ten pound price cut to the PlayStation 2, a console which was already being unofficially discounted by many retailers anyway. Certainly, there's an argument that Sony should save itself for the inevitable PS3 blitz the Tokyo Game Show in a few weeks' time, but quite frankly, given the intense negativity surrounding both the company and its forthcoming console in the specialist media - much o...
In terms of performance, I think that the PS3 and the Xbox 360 will essentially be a wash. We ran the numbers a while back and the two systems come up surprisingly close in theoretical peak performance, despite the one year difference in release dates. However, I know for a fact that we have a great advantage in software and services—our development environment and tools are years ahead of the competition, and this will ensure that Xbox 360 game developers can easily realize all of this perfo...
When you break down the numbers, Xbox 360 has provably more performance than PS3. Keep in mind that Sony has a track record of over promising and under delivering on technical performance. The truth is that both systems pack a lot of power for high definition games and entertainment.
However, hardware performance, while important, is only a third of the puzzle. Xbox 360 is a fusion of hardware, software and services. Without the software and services to power it, even the most...
Just like with the PS2's Emotion Engine, with its missing L2 cache, the Cell is designed for a type of game programming that accounts for a minor percentage of processing time.
Sony's CPU is ideal for an environment where 12.5% of the work is general-purpose computing and 87.5% of the work is DSP calculations. That sort of mix makes sense for video playback or networked waveform analysis, but not for games. In fact, when analyzing real games one finds almost the opposite distribution of general purpose computing and DSP calculation requirements. A relatively small percentage of instructions are actually floating point. Of those instructions which are floating-point,...
Based on measurements of running next generation games, only ~10-30% of the instructions executed are floating point. The remainders of the instructions are load, store, integer, branch, etc. Even fewer of the instructions executed are streaming floating point—probably ~5-10%. Cell is optimized for streaming floating-point, with 87.5% of its cores good for streaming floating-point and nothing else.
Cell's streaming floating-point work is done on its seven DSP processors. Since geometry processing is moved to the GPU, the need for streaming floating-point work and other DSP style programming in games has dropped dramatically.
click my Factual posts as Offensive...I would have to say NJ. He has done it before. He has been busted many times with multi accounts. But I'm going to make you work boy. lol....You ready? The truth to sony fans is like kryptonite is to super man. Only yall are little girlies. Can't handle the truth huh....well there is a lot more where that came from girls.
ATI did clarify that although Microsoft isn't targetting 1080p (1920 x 1080) as a resolution for games, their GPU would be able to handle the resolution with 4X AA enabled at no performance penalty.