Table 1. Comparison of Alpha 21164 and 21264 Processors

21164 (ev5,ev56)                     21264 (ev6, ev67)
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Dual issue                              Quad issue
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Simple branch predictor                 Tournament branch predictor
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Direct mapped, write-through cache      Two-way set associative cache
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Simple instruction scheduling rules     Complex instruction scheduling rules
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                                        Roughly twice the bandwidth of the 21164
                                        New instructions: WH64, CTLZ, CTTZ
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