With reference to Table 2.4, we see that the relative performance of the IBM 360 Model 75 is 50 times that of the 360 Model 30, yet the instruction cycle time is only 5 times as fast. How do you account for this discrepancy?
Table 2.4
Key Characteristics of the System/360 Family

Model 30 Model Model Model 40 256K 0.8 0.625 3.5 Model 75 512K 16.0 Characteristic 50 256K 2.0 65 512K 8.0 0.25 21 64K Maximum memory size (bytes) Data rate from memory (Mbytes/sec) Processor cycle time us) Relative speed Maximum number of data channels Maximum data rate on one channel (Kbytes/s) 1.0 0.2 10 4. 800 250 1250 1250