They are both similarly fast in single threaded applications. CPU-Boss says the i3 is 2% better, while CPU-World says the i5 is 4% better. http://cpuboss.com/cpus/Intel-Core-i5-3450S-vs-Intel-Core-i3-3245
http://www.cpu-world.com/Compare/502/Intel_Core_i3_i3-3245_vs_Intel_Core_i5_i5-3450S.html
They are both similarly fast in single threaded applications. CPU-Boss says the i3 is 2% better, while CPU-World says the i5 is 4% better. http://cpuboss.com/cpus/Intel-Core-i5-3450S-vs-Intel-Core-i3-3245
http://www.cpu-world.com/Compare/502/Intel_Core_i3_i3-3245_vs_Intel_Core_i5_i5-3450S.html