This is the most rigid of all models. After any update, any subsequent access by any process will return the updated value.

In this model, any read on a data item, X, returns the value corresponding to the result of the most recent write of X. This is depicted in the following diagram:

Here, P1 writes a to X, and when P2 reads X later on, it gets a.

This is the most rigid form of consistency. Its implementation requires absolute global time and implementation of the fact that a write done on any process is simultaneously available on all processes. Building such guarantees is considered mostly impossible.