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[omkaranathan]

Raistmer,

The new SDK is going to be released soon.

[fulcrum_xyz]

hi

it would be really great if you could post your ported OpenCL FFT code...

thanks

[Raistmer]

Originally posted by: fulcrum_xyz

hi




it would be really great if you could post your ported OpenCL FFT code...




thanks

New SDK works with default parameters values.
Updated oclFFT sampel can be obtained here:
http://developer.apple.com/lib...troduction/Intro.html

[fulcrum_xyz]

Thanks Raistmer, I have the apple version...and currently porting it to run on my OpenSUSE 11.2.

So, I was wondering if you had already ported it to a linux (non MacOS version) and if you could share that ?

thanks again...

P.S: I have taken a look at the OpenCL SDK FFT sample, that seems to be very preliminary and support very minimal parameters (on 1D, no batching, no complex)...

[Raistmer]

Originally posted by: fulcrum_xyz

Thanks Raistmer, I have the apple version...and currently porting it to run on my OpenSUSE 11.2.




So, I was wondering if you had already ported it to a linux (non MacOS version) and if you could share that ?




thanks again...




P.S: I have taken a look at the OpenCL SDK FFT sample, that seems to be very preliminary and support very minimal parameters (on 1D, no batching, no complex)...

SDK sample just not worth mention actually. It's hardwired to single FFT size, just some technique demonstation, not useful piece of code for FFT.
Usable FFT was promised in next SDK release, will see

About linux porting there was attempt with earlier bugged SDK (2.0) and as far as I can remember it works even better than windows part. So there should be no problems on linux with current SDK.
With SDK 2.0 default base radix of 128 failed. value of 32 was used. But currently I see better performance on 1D 32k-size transform for old 128 value (and it works).
Smaller base radix of 32 better suited for app that uses 1D FFT with different sizes from 8 to 128k.
There are few parameters for playing. I use HD4870 GPU, obsolete hardware from AMD point of view , so someone with newer HD5xxx card could see different performance optimum.

[fulcrum_xyz]

hey thanks for the info...

i wanted to benchmark some (mostly 2^x) 2D FFTs on OpenCL on the GPU

On the NVIDIA cars, i think we can safely assume that the performance with OpenCL with <= cufft performance ( ~ 20 - 40 % ). I am not sure if NVD is even thinking of a OpenCL version of theier library anytime soon...

But, with the ATI cards its not all the clear...so I was looking to get an estimate for the same (it would be also great if someone from AMD could fill us in if they have nay information in this regard..)

So, with I've concluded that porting the Apple OpenCL fft and benchmarking it both the hardware is the best way to go (with the lack of any futher info...)....'

[Raistmer]

You could find this article helpful also:
http://www.bealto.com/gpu-fft_ref.html