Speed test demo -see studio for more speed test demos: http://scratch.mit.edu/studios/795672/ ------- This one shows that referencing a variable takes slightly longer than referencing a custom block parameter. That means if you are going to reference the same variable (or several) lots of times, without it changing, it could be slightly quicker to actually send it into a custom block as a local parameter, and reference it in there like that. (But it does have to be a *lot* of times to make a significant difference – here it accesses them a million times, with ~0.1s difference.)