# Maximum box size?

Hi,

I am currently trying to calculate a structure of a large complex with a box size of 512 pixel on a computer with a GTX1080. It keeps reaching the “MemoryError” in pyfft. I assume this is due to a limit in the graphic card memory. Is there a way to estimate how much memory is need for a given boxsize ?

I found in this forum the rules of 20*(boxsize)^3 for version 0.3.9, but it obviously doesn’t work with the current version.

Thank you for your help

Error message if that’s help :

Traceback (most recent call last):
File “cryosparc2_worker/cryosparc2_compute/run.py”, line 78, in cryosparc2_compute.run.main
File “cryosparc2_worker/cryosparc2_compute/jobs/refine/run.py”, line 363, in cryosparc2_compute.jobs.refine.run.run_homo_refine
File “cryosparc2_compute/sigproc.py”, line 853, in compute_all_fscs
File “cryosparc2_compute/sigproc.py”, line 803, in get_fsc
File “cryosparc2_compute/fourier.py”, line 110, in fft
File “cryosparc2_compute/fourier.py”, line 74, in fftcenter3
fv = fftmod.fftn(tmp, threads=th)
File “/opt/cryosparc/cryosparc2_worker/deps/anaconda/lib/python2.7/site-packages/pyfftw/interfaces/numpy_fft.py”, line 183, in fftn
calling_func, normalise_idft=normalise_idft, ortho=ortho)
File “/opt/cryosparc/cryosparc2_worker/deps/anaconda/lib/python2.7/site-packages/pyfftw/interfaces/_utils.py”, line 125, in _Xfftn
FFTW_object = getattr(builders, calling_func)(*planner_args)
File “/opt/cryosparc/cryosparc2_worker/deps/anaconda/lib/python2.7/site-packages/pyfftw/builders/builders.py”, line 364, in fftn
avoid_copy, inverse, real)
File “/opt/cryosparc/cryosparc2_worker/deps/anaconda/lib/python2.7/site-packages/pyfftw/builders/_utils.py”, line 127, in _Xfftn
output_array = pyfftw.empty_aligned(output_shape, output_dtype)
File “pyfftw/utils.pxi”, line 172, in pyfftw.pyfftw.empty_aligned
File “pyfftw/utils.pxi”, line 201, in pyfftw.pyfftw.empty_aligned
MemoryError

These are CPU FFTs from pyfftw, not CUDA FFTs. How much memory does your workstation have?

What if you change the computational minibatch size from 2000 to a smaller value like 1000?

(I assume these are all 1 class jobs or else you would have to multiply the space based on the formula you quoted, 2.5 GB / reference in your case).

Dear Daniel,