Suppose a computer M3 has an average CPI of 2.7 and a clock rate of 3.7 GHz. Please answer the following: (a) Calculate the runtime for a program P with 22,933 instructions, which uses an accelerating co-processor 45 percent of the time. (b) determine how much faster (or slower) the accelerator needs to run for P to run 1.5 times (1.5X) as fast on M3 with the faster (resp. slower) accelerator. Hint: First set up your equation for Amdahl’s Law, and see if it can indeed be solved… a negative result means that the requested improvement is infeasible…
a)
Rin tine = CPI*Instruction count*/Clock rate
2.7 * 22933/(3.7*10^9)
= 16734.8918919 * 10^-9
= 16.7 micro seconds
b)
To make the system run 1.5 times faster we have to make sure that 45% is covering that speed
first of all system to be 1.5 times faster needs to run in = 16.7/1.5 = 11.1333333333 microseconds
so, 11.1333333333 = (2.7 * 22933/(3.7*10^9)) * 0.55 + 0.45 * x
so x = (11.133333-9.20419054054)/0.45 = 4.28698324324
which means the co processor needs to be 4.28698324324 times faster.
Suppose a computer M3 has an average CPI of 2.7 and a clock rate of 3.7...
Suppose a computer M3 has an average CPI of 2.7 and a clock rate of 3.7 GHz. Please answer the following: (a) Calculate the runtime for a program P with 22,933 instructions, which uses an accelerating co-processor 45 percent of the time, and (b) determine how much faster (or slower) the accelerator needs to run for P to run 1.5 times as fast on M3 with the faster (resp. slower) accelerator.
Suppose we have developed new versions of a processor with the following characteristics: Version Voltage 1.5 V 1.2V Clock rate 2.4 GHz 3GHZ a) How much has the capacitive load varied between versions if the dynamic power has been reduced by 15%? Assuming that the capacitive load of version 2 is 70% the capacitive load of version 1, find the new voltage value for version 2 if the dynamic power of version 2 is reduced by 35% from version 1....