[Insight-users] Speed

[Dan Mueller]

Did you compile in Release mode?

On 9 February 2011 10:33, Gib Bogle <g.bogle at auckland.ac.nz> wrote:
> I have encountered something that surprises me, and I'd like to hear any
> comments.  I'm not being critical, it's just interesting.  I was using
> MeanImageFilter, and was surprised at how slowly it ran on my image.  Since
> the filter function is very simple, I decided to code up my own version, to
> see if I could get it done faster.  I'm not really a competent C++
> programmer, so I've just implemented an efficient algorithm in C.
>
> I'm testing with a greyscale image 955x963x100, on a Core i7 W7 machine (4
> cores, 8 threads).  Setting each filter radius to 5, the MeanImageFilter
> processing takes 1184 sec, using all 8 threads (100% CPU usage).  My own
> averaging code takes 105 sec, using only a single thread (12.5% CPU usage).
>
> Why the big difference?
>
> Gib