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Timeline gap in culaDeviceDsyevx

PostPosted: Wed Aug 27, 2014 8:02 am
by ujfalusilaci
Hi I found a strange about 0.2 long timeline gap in culaDeviceDsyevx with nvvp, see the attached picture between 0.5s...0.7s. Image

I use the following frame function to call culaDeviceDsyevx:

Code: Select all
void cu_Diagonalize_dsyevx(int N, int num_eigvals, double* Hamilton_d, double* eigvals_d, double* eigvecs_d, int* ifail_d, culaStatus* status)
{
  int num_found_eigvals=0; //Number of found eigenvalues of method
  char jobz='V', range='I', uplo='L';
  double vl=0, vu=0, abstol=1e-8;
  int il=1, iu=num_eigvals;

  *status=culaDeviceDsyevx(jobz, range, uplo, N, Hamilton_d, N, vl, vu, il, iu, abstol, &num_found_eigvals, eigvals_d, eigvecs_d, N, ifail_d);
}


I use a graphic card: GeForce GTX 650 Ti with compute capability 3.0

How can this gap removed? 0.2s is a really long time for the GPU not to be busy at all.

Re: Timeline gap in culaDeviceDsyevx

PostPosted: Thu Aug 28, 2014 2:39 am
by ujfalusilaci
It gets even more weird if I increase the matrix size, now there is a 7s long gap:
Image
Additional information: I use CULA dense R17 and CUDA 5.0.