Synchronous and asynchronous updating in cellular automata Live cam xxx hack
These models relax the normal requirement of all nodes having the same update rule. Nodes within a block were updated synchronously, but blocks were updated asynchronously.They experimented with three schemes: (1) at each time step, a block is chosen at random with replacement; (2) at each time step, a block is chosen at random without replacement; (3) at each time step, a block is chosen according to a fixed update order.Some cells may be updated more than once, some not at all during one time step.
At each time steps, N updates are performed, selecting a cell at random at each step.
Several studies have implemented asynchronous models and found that their behaviour differs from the synchronous ones.
Bersini and Detours (1994) have shown how sensitive Conway's Game of Life is to the updating scheme.
In classical cellular automata the local function is always applied synchronously to all the cells, i.e.
they are evaluated and take their new values at the same moment. In analogy to a continuous time process the cells may also be evaluated and take their new states one after the other. Since this term has been used for quite different things in literature we would like to note that we do not mean a system like in  where the cells take their new values with a delay but are updated synchronously.