Hi, I just upgraded to UFRaw 0.15 and noticed that performance when rendering previews has deteriorated severely. Operations that used to complete almost instantly sometimes take close to a full minute to complete, making the software close to unusable.
It turns out that the parallelization of the rendering is at fault, disabling OpenMP in the application significantly improves performance. To be more specific, it is the parallelization of the 'develope' procedure that is causing the performance issues when rendering previews. If I understand things correctly, the count parameter to that procedure is related to the number of pixels to process. Looking at the procedures called, I highly doubt that the current threshold of 32 pixels(?) for parallelization would offset the cost of thread creation and the synchronization at the end of the parallel region. I disabled the parallelization of that particular region and the performance returned to what I'm used to from older versions. Since it was the slow previews that bothered me the most, I played around a bit with parallelizing that part. Making render_preview_image render several subareas in parallel instead seemed to yield a better result. Sorry for complaining so much... I really like UFRaw and hope it continues to an invaluable image processing tool! //Andreas ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! http://p.sf.net/sfu/devconference _______________________________________________ ufraw-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/ufraw-devel
