Why does a CPU need a GPU?

[Lythe]

Why does a computer need multiple processing units?

Wouldn't having just one processing unit be faster, so they don't have to wait for each other?

So why can't the CPU process everything?

Wouldn't supercomputers be able to render graphics at unmeasureable frames and detail of complexity?

Thanks for the response.

 

[bla!!]

It has to do with their internal architecture and the way each processes the data sent to it.

Where your CPU is set up to handle several different types of data passed into it (it has many different instruction sets, specifcially designed pipes for numerical processes, etc..), the GPU is specialized for graphics processing. I'm not positive, but I'm guessing within the several pipes within the GPU there are explicit instruction sets for swapping pixels, probably some for smoothing etc..

You're right that it could all be acomplished by the CPU, but having a dedicate processor just for graphical processing actually increases the speed.

 

[bla!!]

Here's a nifty article outlining some of the differences.

http://hankfiles.pcvsconsole.com/answer.php?file=420

Or if you want to do some research yourself, look up info on the IA32 architecture vs some GPU architecture.

 

[Lythe]

So I guess you could run a computer w/o a graphics card?

How might someone design the archeticture for a graphics processer?

Thanks for the help.

 

[Codeine]

Its pretty easy to understand. Heres a single unit

Single Unit processing 1.2.3.4.5.6.7.8

Dual Unit

Unit(1) 1.3.5.7
Unit(2) 2.4.6.8

So it shares work rather then does it all. Witch is better.

 

[Lythe]

So the two would need a third unit to compile the data back together?

 

[Apokalipse]

some motherboards have onboard video, but that means it uses the main CPU and the RAM to do the job, which means less resources for everything else
if your CPU processes everything, it becomes slower from higher demand, plus the CPU is not designed for processing graphics, and often doesn't have some of the features to play games like a proper GPU does
there are 2 main companies researching graphics cards only; ATI and Nvidia. they specialise in graphics so the cards end up being better for the job.
the same thing goes with CPU's, except it's AMD and Intel specialising in this department

there are 2 companies each for graphics cards and CPU's, competing against each other has brought on better graphics cards/CPU's at a faster rate

 

[bigdawgjts2663]

apok good view, he is right! Although there are subcatagories of each company (i.e. eVGA for nVidia, and so on) the two compete for sales, which end up in better performance! and a GPU in a comouter does work better than intagrated grpahics. data is sent so fast through computers that the time it takes the data to get to the GPU to your monitor is not even measurable, just like my geaphics card is displaying what I am typing on this screen so fast I notice no difference. The only time you will notice a difference is when your CPU lags, and then subsequently your comp freezes, and your GPU lags as well b/c the info is sent thorough the CPU and then the GPU processes the info to your monitor at a higher quality. Pretty sure thats how it works, but I am sure it is MUCH more complicated than that.

 

[grego]

Actually, Lythe, in the future our CPUs main not be at all dependent upon GPUs. I think it was in the current issue of Maximum PC that they were talking about a possible direction of CPUs that could lead them to being so powerful they really wouldn't need a seperate GPU for top of the line performace. I believe they likened the concept to the proccesor in the upcoming Playstation3.

 

[Lythe]

Actually, Lythe, in the future our CPUs main not be at all dependent upon GPUs. I think it was in the current issue of Maximum PC that they were talking about a possible direction of CPUs that could lead them to being so powerful they really wouldn't need a seperate GPU for top of the line performace. I believe they likened the concept to the proccesor in the upcoming Playstation3.

So shouldn't supercomputers be able to bench everything faster than any desktop PCs?