Web I use the filter "flou de surface" I running more than 10minutes With MacBook Pro core I7. I think it's not normal??
Without information like version, OS, size of the image, hardware, Performance Preference settings, … I don’t think one can fully judge the performance.
Please read these and proceed accordingly:
Also, how long the filter might take to run depends on the size of the image, the depth of the image, and the settings specified for the filter… none of which you have told us.