There's a brilliantly-named paper on this: Why Nothing Matters: The Impact of Zeroing. Efficient zeroing is something JVMs put some thought into. Well, with a

There's a brilliantly-named paper on this: Why Nothing Matters: The Impact of Zeroing. Efficient zeroing is something JVMs put some thought into. Well, with a notable exception, in HotSpot itself: We were able to substantially improve its performance by using memset() to perform the zeroing. [0] (PDF) http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.225.9497&rep=rep1&type=pdf http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.225...