You can optimise for speed, power consumption or memory use & tiny changes can have a negligible or huge impact, but what should you optimise and most importantly, when? Dr Steve Bagley has an example! This video was filmed and edited by Sean Riley. Computer Science at the University of Nottingham: Computerphile is a sister project to Brady Haran's Numberphile. More at Thank you to Jane Street for their support of this channel. Learn more: