weird cufft problem - works sometimes but not other times problem with cufftExecC2C working only spo

[mr_bhen]

Hi all,

I am having a strange problem running FFT on CUDA.

I’ve been using the CUDA FFT algorithm in numourous programs for over a year now so I am familiar with it. Ive worked in 32 bit and 64 bit and I am familiar wih all the SDKs from 2.3 up to 3.2. I am currently using a Windows 7 32 bit OS, with CUDA SDK 3.2 and VS2008.

Anyways I have a programs that processes 2D images - I must use the CUDA fft algorithm at least 10 times in the program. I am using in place FFTs like the following

// Step 1: CUFFT plan
cufftHandle plan;
cufftPlan2d(&plan, Ny,Nx, CUFFT_C2C);

// Step 2: execute fft algorithm - Transform signal and kernel
int SIGN = -1;
cufftExecC2C(plan, (cufftComplex )d_input, d_input, SIGNCUFFT_FORWARD);

…
cufftDestroy(plan);

The problem I am having is that sometimes the code works and sometimes it just returns the original dataset, d_input, with no changes at all. When I reboot it solves the problem temporarily, but it comes back usually after about 3-4 runs of the fft,

Any ideas anyone?

Thanks
Bryan

[eldadk]

Hi all,

I am having a strange problem running FFT on CUDA.

I’ve been using the CUDA FFT algorithm in numourous programs for over a year now so I am familiar with it. Ive worked in 32 bit and 64 bit and I am familiar wih all the SDKs from 2.3 up to 3.2. I am currently using a Windows 7 32 bit OS, with CUDA SDK 3.2 and VS2008.

Anyways I have a programs that processes 2D images - I must use the CUDA fft algorithm at least 10 times in the program. I am using in place FFTs like the following

// Step 1: CUFFT plan

cufftHandle plan;

cufftPlan2d(&plan, Ny,Nx, CUFFT_C2C);

// Step 2: execute fft algorithm - Transform signal and kernel

int SIGN = -1;

cufftExecC2C(plan, (cufftComplex *)d_input, d_input, SIGN*CUFFT_FORWARD);

…

cufftDestroy(plan);

The problem I am having is that sometimes the code works and sometimes it just returns the original dataset, d_input, with no changes at all. When I reboot it solves the problem temporarily, but it comes back usually after about 3-4 runs of the fft,

Any ideas anyone?

Thanks

Bryan

Hi Bryan,

It sounds to me like some of your cufft calls fail on the subsequent runs.

You should verify that the cufft functions return CUFFT_SUCCESS.