 The VAXft Model 410, code named ""Cirrus II"", was a mid-range model announced on 18 March 1991 alongside three other models.Originally supposed to ship in June or July 1991, it was delayed until September 1991, with the reason given by DEC being that it wanted to tune a new release of VMS for the system.The Model 410 was identical to the Model 310, but used the KA550 CPU module containing a 28.57 MHz (35 ns cycle time) SOC microprocessor with 128 KB of external secondary cache.