The alternative definition of a coherent system is via the definition of sequential consistency memory model: "the cache coherent system must appear to execute all threads’ loads and stores to a "single" memory location in a total order that respects the program order of each thread". Thus, the only difference between the cache coherent system and sequentially consistent system is in the number of address locations the definition talks about (single memory location for a cache coherent system, and all memory locations for a sequentially consistent system).