within the same time frame, while computer clusters used parallelism outside the computer on a commodity network, supercomputers began to use them within the same computer. following the success of the cdc 6600 in 1964, the cray 1 was delivered in 1976, and introduced internal parallelism via vector processing. while early supercomputers excluded clusters and relied on shared memory, in time some of the fastest supercomputers (e.g. the k computer) relied on cluster architectures.