8
$\begingroup$

When VASP 5 was released, the performance was mostly slower than our make of VASP 4.6. I wrote it off as an optimization issue, and went on in my life. Then, in VASP 5.2, with the release notes, I realized that the it was all due to slower FFT, and is now fixed. Is there any way for me, as a user, to tell if the VASP make that I am using is built with the faster FFTW?

Improve this question
$\endgroup$
1
  • $\begingroup$ If you are still working with VASP and run into any questions, you might be interested in Matter Modeling SE $\endgroup$
    – Tyberius
    Nov 11 at 16:40
6
$\begingroup$

There are a few possibilities:

  • Ask whoever built it. :)
  • Run strings vasp | grep -i fft and see if there's evidence of the version buried in the executable.
  • Run ldd vasp and look for a dynamically linked fft library. This last option is unlikely to produce results because you're more likely to have a static FFTW library (if I recall the build process for FFTW correctly).
Improve this answer
$\endgroup$
2
  • 4
    $\begingroup$ To expand on this answer, you could also try: nm vasp | grep fftw to take a look for some of the FFTW symbols assuming that the executable hasn't been stripped. $\endgroup$
    – Aron Ahmadia
    Nov 30 '11 at 13:13
  • $\begingroup$ That's a great point, Aron, though I recommend grep -i in this context. $\endgroup$
    – Bill Barth
    Dec 2 '11 at 15:04

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.