teraflops?

[scottishbmxer]

i was reading through the specs of the ps3 and its keeps going ojn about teraflops and how teh ps3 has 2.

what is a tearflop?

 

[killians45]

a floating point calculation. I would just ignore it as there are many ways to equate it.

 

[scottishbmxer]

so compared to a ghz, how big is it? or is it just a way to make the general public think its better than it is?

 

[Phoenix1]

Floating point operations per second is a much better way of measuring a microprocessor's speed than the clock speed. For example an AMD Athlon running at 3GHz outperforms an Intel Pentium 4 running at the same clock speed. An Athlon has a higher flops rate than a Pentium running at the same clock speed.

The opposite of your question is true. Advertising clock speed is a way to make the general public think it is better than it is.

 

[killians45]

I'd have to say yes and no on that. It depends on the programmer and how they are calculated. In comparing between the PS3 and 360, this right here says it all:

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 powerful hardware becomes inconsequential. Xbox 360 games—by leveraging cutting-edge hardware, software, and services—will outperform the PlayStation 3.

He goes on to say:

Even ignoring the bandwidth limitations the PS3Â’s GPU is not as powerful as the Xbox 360Â’s GPU.

AndÂ…

The PS3 does have the additional 7 DSPs on the Cell to add more floating point ops for graphics rendering, but the Xbox 360Â’s three general purpose cores with custom D3D and dot product instructions are more customized for true graphics related calculations.

DETAILED ANALYSIS OF PERFORMANCE SPECIFICATIONS

CPU
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 CellÂ’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 PS3Â’s main CPU. They are not designed for or efficient at general purpose computing. DSPs are not appropriate for game programming.

Xbox 360 has three general purpose CPU cores. The Cell processor has only one.

Xbox 360Â’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 processorÂ’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.

CellÂ’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.

Just like with the PS2Â’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.

SonyÂ’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, very few involve processing continuous streams of numbers. Instead they are used in tasks like AI and path-finding, which require random access to memory and frequent branches, which the DSPs are ill-suited to.

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.



Now, although the site is a biased site, the specs and info, however, is utterly accurate. Plus, there is also the problem with programming difficulties. Last check, XBox360 was a pain to develope for, the PS3 even harder. Sony is, at last check, having problems with backwards compatability as well because of the completely new architecture.

So, in summation FPS are not the tride and true way to determine what is best UNLESS it is done via similar circumstances because FP can be calculated many different ways and it also depends on what these calculations are a summation of. True, the DSP are monsters when it comes to number crunching, but it also lacks in many key areas. A shame, really... the cell idea is a great one, but I think it wont truelly show its glory until the next generation when sony works the bugs out on how to better benefit the developers with a more friendly programming interface AND better branch and cache for each.-

 

[tech_101]

Wow!!!... lots of info to read. I only read half. So umm... from what I read it seems the Xbox 360 is better in your eyes.
While I dont know all the specs of either system i still think ill have to go with the Ps3. Theres a simple reason behind that, I liked the Ps2 better then the Xbox. In conclusion ps3 now and xbox360 later.

 

[Lonewolf5460]

good i read like half too looks like the xbox will have a bigger fanbase this time around.

 

[killians45]

tech_101, out of all the arguments for and against the XBox360 vs PS3 that is perhaps the best answer I've heard. No sarcasm, either. Arguing architecture is moot right now as the true 'being made at the factory' PS3 OR Revolution, for that matter, hasn't happened yet. All other arguments are, for lack of a better word, stupid. Is the XBox360 awesome? Oh, hell yes. The best answer to give as of now is that you just like the PS better because you liked the original console specific game. That says it all. However, the points above are valid. Many are pointing to the DSP processors as being amazing, when in fact, while it is nice for streaming, AI and physics... thats about all they are good for. Now, if they were general purpose processors with good branch prediction then I'd have to say ****, that is absolutley amazing. As of now I'd say they will be fairly equal, with the PS3 better at processing and the 360 better on the graphics side. As of now, the PS3 is also haveing the same problems as the 360 with backwards compatability and will most likely need software emulation, but that verdict is still out.

 

[zfagerstrom159]

Teraflops are 1000 gflops i think