[cctbxbb] Removal of Boost.Thread support

[Pascal]

Le 15/08/2012 21:04, Nathaniel Echols a écrit :
> 
> The best use of OpenMP that I can think of would be to parallelize the
> direct summation code, which is so inefficient that Amdahl's Law
> shouldn't be as big of a buzz-kill as it was for the parallelized FFT
> calculations.

You can use OpenMP for direct summation code for the structure factors
calculation. It's working very well.

But OpenMP is not only the only thing you can look at. I can work 4
times faster on a single core compared to cctbx by using optimised
trigonometric functions[1] and SIMD friendly code. By the way is double
precision really necessary? The code I have written is about 3 times
faster is single precision than the double precision.

However I don't know how similar the calculation of the gradient is so I
don't if the same kind of method is applicable.

I am using the structure factors calculation as a playground for
optimization :).

Pascal

[1] Sleef library: http://shibatch.sourceforge.net/