# CUDA Vs CELL



## ADF (Jun 25, 2008)

I donâ€™t know if anyone else has noticed but CUDA (Nvidia GPU application acceleration) is stepping into quite a few of the markets Cell is selling to, desktop supercomputing basically. CUDA is mostly fighting against Intel but I wouldnâ€™t be surprised if it steps enough on Cells toes to warrant a response.

It isnâ€™t too surprising when you think about it; Cell is looking into scientific and medical computing, so is CUDA. Cell is going into multimedia acceleration, so is CUDA.

Developing for CUDA is most likely easier than Cell because it uses an extended form of C or C++, which are common programming languages. Any G80 or better system is CUDA ready; there is actually a market of consumers who can run applications based on CUDA, how many consumer computers are equipped with Cell? You will be lucky to find one outside of a specialized device like a TV or PS3.

Which one do you think is going to become the industries preferred standard? I personally think CUDA, especially if they can convince ATI to jump on board, simply because install base is much more wide spread than Cell. You hear about scientists hooking up multiple PS3s to do scientific calculations, I think they would much prefer multiple TESLA GPUs on a platform they can totally control.

Also what do people think of CUDA overall?

[edit]

Applications of CUDA and their estimated performance improvement over CPUs.


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## Draco_2k (Jun 25, 2008)

CUDA. It's a way more native environment to most developers, it's easier to adapt to, and it's just as effective as CELL, it seems.

Occam's razor.


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## Pi (Jun 25, 2008)

I worked with someone who was trying to port John The Ripper to Cell. 

Won't work; most applications these days depend on global state. So while cell may be technically superior, nobody writes programs that can cope. Oh well.


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## ADF (Jun 25, 2008)

My limited experience with CUDA is with the Nvidia Folding@home app, it is a beta with drivers due out next month yet I am already able to get through a work unit four times faster than the PS3.

This is with a 8800GT by the way, a Â£115 GPU, god knows what it will be able to do when they finish the app and release drivers to help support it. The good thing about using my PC for this sort of thing is I can actually use it while I'm donating performance; I'm typing this, listening to music and watching YouTube videos while also crunching a F@H work unit every hour. A PS3 user would have to run the app and stare at a screensaver until they get bored, this is why many of them run it when they are not using the PS3 for anything.

Another impressive example of CUDA is this YouTube video where they use it to make a joke out of a high end quad core processor. The software they are showing here will apparently be made available for 'free' with future Nvidia GPU purchases, there is also going to be a downloadable version but I doubt it is free.

If you have a 200 series/9800GTX there is also a driver out  that adds GPU acceleration for the Ageia PhysX maps in UT3, so your GPU acts as a PPU to accelerate the physics in the game. Currently they are the only supported cards, but full CUDA GPU supported drivers will eventually come out.

What I like about CUDA is it's here now for anyone to mess with; Cell is something only Linux programmers with a PS3 or businesses can poke at, unless you are one of the tiny few with a Cell processor in their TV. If you have a 8400 or better post G80 GPU you are already CUDA ready, the performance is already available to be tapped it is just a matter of the software coming out.

Cell cannot boast that, which is why I think CUDA will be much more popular.


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## Xenofur (Jun 26, 2008)

Can you put in simple words what CUDA actually is?


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## ADF (Jun 26, 2008)

Xenofur said:


> Can you put in simple words what CUDA actually is?


The CPU is a general purpose processor; meaning it is a jack of all trades, it can do everything moderately well. The GPU is a specialised processor, it is really good at doing some tasks and bad at others. When you are not gaming that GPU is sitting idle 90% of the time, doing nothing, one day someone decided why not see what it can do if it works together with the CPU in processing tasks?

CUDA takes the tasks the GPU is good at and moves them onto the GPU, giving a several fold increase in performance. This may be a 1.5x increase or a 260x increase, it depends on how much a specific tasks benefits from what the GPU is good at.

When used in games 10-15% of your GPUs performance can be dedicated to what GPUs are good at like AI or physics, providing significant game play improvements at the cost of a few fps.


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## karoug (Jun 29, 2008)

From what I've seen so far the biggest difference between how GPUs and CPUs operate is that GPUs do much more in parallel while a processor is more linear/threaded.

So, while your CPU might run several threaded applications and give each their slices of time in turn a GPU will do everything at once up to its capacity. That's where those stream processors come into play and why they are so important for folding. However, ATI and Nvidia seem to implement streaming differently so that Nvidia seems to perform better even against an ATI card with seemingly better specifications.  However, from what I've seen ATIs use less power, cost less to produce, and are more stable.

So, a GPU is good for doing something like rendering and folding while the CPU can better react to the results of immediate operations.

I don't know what the futures of CUDA and Cell will be since having two competing standards can cause development headaches. I thought it was bad having to write html & javascript that works for Internet Explorer and Mozilla!


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## Draco_2k (Jun 29, 2008)

karoug said:


> I don't know what the futures of CUDA and Cell will be since having two competing standards can cause development headaches. I thought it was bad having to write html & javascript that works for Internet Explorer and Mozilla!


Don't forget Opera, Safari, and older versions of FF and IE!


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## Data_stalker (Jun 29, 2008)

I'll go with Cuda, just cause I'm a Mopar fanboy of the old Barracudas....


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