Solve ALL the exercises

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1. 80% of a program running in a quad-core CPU can be parallelized. What is the maximum speed-up? What would be the maximum speed-up if the number of cores approached infinity? 2. There are two parallel threads, A, B and C, both running the following code in a SMP computer x = x + 5; System.out.println(x); The architecture is MIPS, in which the statement x = x+ 5 is compiled to: lw $80, 0(x) addi $80, $50, 5 sw $s0, 0 (x) If the thread instructions can be interleaved in an arbitrary manner (non-deterministic) what will be the possible outputs, if x is initially 0? 3. Suppose you want to perform two sums: one is a sum of 5 scalar variables, and one is a matrix sum of a pair of two-dimensional arrays, with dimensions 50 by 50. What speed-up do you get with 4, versus 10, versus 100 processors