[:((] i could propose it for the new version

i've tried to render an image with advanced rendering tools, but when i choose silk instead of glossy the rendering process take up to 15 minutes for a 1024x768 image, my computer' hardware is: asrock x58 deluxe3, core i7 930, 6gb ram, raid 0 hdd samsung (2x500gb), 2x hd5850

is this a plug-in bug, or it is too heavy to compute?