The first processors of the Alpha family were designated the DECchip 21064 series (the "21" signifying the 21st century, "0" corresponding to the processor generation and the "64" indicating 64 bits), also code-named EV4. Internally, Alpha processors were also identified by EV numbers, EV officially standing for "Extended VAX".
The first few generations of the Alpha chips were some of the most innovative CPUs of their time. The EV4 was the first CMOS microprocessor whose operating frequency rivalled higher-powered minicomputers and mainframes.
The EV4 core is a dual-issue (it can issue 2 instructions per CPU clock) superpipelined core with integer unit, floating point unit and branch prediction. It is fully bypassed and has 64-bit internal data paths and tightly coupled 8 KB caches, one each for Instruction and Data. The caches are write-through.