Improvements at the physical network layer have enabled technologies such as 10 Gigabit Ethernet. Single core end-systems are unable to fully utilise these networks, due to limited clock cycles. Using a Multi-core architecture is one method which increases the number of available cycles, and thus allow networks to be fully utilised. However, using these systems creates a new set of challenges for network protocol processing, for example, deciding how best to utilise many cores for high network performance. This paper examines different ways the cores of a multi-core system can be utilised, and, by experimentation, we show that in an eight core system deciding which cores to use is important. In one test, there was a 40% discrepancy in CPU utilisation depending on which cores were used. This discrepancy results from the resources each core shares, an example being the multi-hierarchy CPU caches, and to which bus the processors are connected.