Consider the case where a program consists of 30% integer instructions, 50% floa

Question

Consider the case where a program consists of 30% integer instructions, 50% floating-point instructions and 20% memory access operations and executes 49 billion instructions.

Let a machine take 205 ps to execute an integer instruction, 686 ps to execute a floating-point instruction and 4 ns to complete a memory access operation.

Assume that we can overclock the processor arbitrarily, thus speeding up the integer and floating-point performance by an arbitrary factor.

How much faster would the processor have to run to complete the task in 30 s?

Explanation / Answer

Total instruction = 49000000000

30% integer instructions = 14700000000 which takes 14700000000*205*.001 = 3013500000 ns

50% floating-point instructions = 24500000000 which takes 24500000000*686*.001 = 16807000000 ns

20% memory access operations = 9800000000 which takes 9800000000*4 = 39200000000 ns

So, total time needed by the program = 3013500000 + 16807000000 + 39200000000 = 59020500000 ns

Now, we want to complete the program in 30 Sec = 30000000000 ns

So, the processesor needs to run ((59020500000 - 30000000000)/59020500000)*100% = 49.17% faster

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects