estimating Throughput and Processor Speed requirements SMAD example Operator types 100 words(600 characters) /min 256 keyboard states implies an 8-bit data word Input data stream=4800 bits/min Each character requires 10 instructions to pI rocess Each word requires 100 instructions to process 16.000 instructions/min=267 instructions/sec
Estimating Throughput and Processor Speed Requirements • SMAD example – Operator types 100 words (600 characters)/min – 256 keyboard states implies an 8-bit data word • Input data stream = 4800 bits/min – Each character requires 10 instructions to process – Each word requires 100 instructions to process • 16,000 instructions/min = 267 instructions/sec
estimating Throughput and Processor Speed requirements SMAD example continued Each instruction takes five clock cycles to read and one to execute CPU must operate at 96,000 cycles/min=1600 cycles/sec =1.6 kHz To store input data and transfer 8-bit instructions to the CPu requires 80 bits/sec for data plus 2136 bits/sec for instruction fetches=2216 bits/sec transfer rate In 24 hours the system will store 6.9 Mbits of data in addition to its 880 bits of stored instructions
Estimating Throughput and Processor Speed Requirements • SMAD example continued – Each instruction takes five clock cycles to read and one to execute • CPU must operate at 96,000 cycles/min = 1600 cycles/sec = 1.6 kHz • To store input data and transfer 8-bit instructions to the CPU requires 80 bits/sec for data plus 2136 bits/sec for instruction fetches = 2216 bits/sec transfer rate • In 24 hours the system will store 6.9 Mbits of data in addition to its 880 bits of stored instructions