Some supercomputer architectures of the 1970s and 1980s , such as the Cray - 1 , used registers up to 64 bits wide , and supported 64 - bit integer arithmetic .
Supercomputer architectures did not support 64 - bit addressing .
Some supercomputer architectures of the 1970s and 1980s , such as the Cray - 1 , used registers up to 64 bits wide , and supported 64 - bit integer arithmetic , although they did not support 64 - bit addressing .