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[[File:output.jpg]]
The cache line size, which in this example is set to 64 bytes, is the first thing that the programme prints. The programme is then run twice, once with a single thread and once with two threads. In each instance, it uses a loop that iterates NUM_ITERATIONS times to increase two counter variables (counter1 and counter2). The runtime and final values of the counter variables are then printed by the program.
The output demonstrates that using more than one thread (479 ms) results in a longer programme execution time. (355 ms). This is due to the fact that the two threads are incrementing two different counter variables, each of which is situated on a different cache line. Because of this, there is competition among the threads for access to the cache lines, which results in cache misses and slower performance. If the two counter variables were on the same cache line, the programme would probably execute more quickly when using multiple threads.
== Sources ==
