DEC Alpha 21164PC (PCA56) processors
Introduction: October 1997
21164PC (PCA56) was introduced on the 17th of March 1997. It was a low-cost version of EV56 designed by DEC and Mitsubishi cooperatively. S-cache was absent as well as accompanying logic, but I-cache size was increased from 8KB to 16KB. Was manufactured with the same CMOS5 process and required a 2.5V/3.3V power supply. Consisted of 3.5M transistors and possessed a die size of 141mm². Core frequencies of 21164PC (PCA56) ranged from 400MHz to 533MHz (TDP from 26W to 35W). Form-factor was changed in favour of IPGA-413. There was also 0.28µ 21164PC (PCA57) manufactured by Samsung. I-cache and D-cache of it were doubled in size, and I-cache was made 2-way set associative. At the same time, transistors' count increased to 5.7M but die size decreased to 101mm². It required lower voltages than PCA56 (2.0V for primary and 2.5V for input-output circuits). Core frequencies of 21164PC (PCA57) ranged from 533 to 666MHz (TDP from 18W to 23W).