Hi there, do you suppose it is possible to use the graphics processor as a slave to the CPU for computing FFTs via openGL? Background is, I want to squeeze every bit of performance out of existing systems and thought that would be a nice thing, but first I don’t know whether this is possible at all, and secondly with openGL I don’t have a clue.
Sorry, FFT = Fast Fourier Transform, basically a method of trying to get the frequency part out of a series of numbers taken from a time series (that part has basically nothing to do with graphics, but essentially this can be performed just by adding and multipliying complex (or real) numbers)
I presume you need the results for something else… you also considered that you might saturate the bus, moving all that data.
I remember a guy, on the OpenGL maillist, proposing the use of the graphics adapter for sound manipulation. A sound idea, but it wouldn’t work in practice for several reasons.
MMX is already considered it’s just to increase the effectiveness and a few days ago I read that the GeForce3 might have a peak performance of several GFlops we thought it could be quite nice to use this also, especially for multiple FFTs of the same data of different lengths the bus shouldnt be a big problem. But anyway, thanks a lot.
Even though the GeForce3 can reach a few Gflops, it’s not the same kind of Gflops as in standard CPU’s. The GeForce is a GPU, which is highly optimized for graphics, and not indended to be a math unit the user can use like that.
For fast FFT you can read some articles for get the most profit of Intel processors from Intel website. Intel also gives free the fastest ever library for loading JPEGS. If your application uses it (it’s pressumible) don’t doubt and try it.
There’s also intel-optimized libraries for
fft and practically any other computational thing you’d like to perform. I believe their latest incarnation is called something like “Intel Performance Primitivies”
You also might want to check out the Fastest Fourier Transform in the West: http://www.fftw.org