The core i5 is faster with 4 cores compared to the core i3 which has 2 cores.
So due to that,it helps in gaming and multimedia.
i5 2430 is always better for 4 physical cores .. but is the purpose ?
@ OP - there ain't much price difference between core i5 2430 and core i5 2500k - 1.5-2k max - so if you can go for i5 2500k along with Biostar TZ68K+ @ 6.8k - you will get a much better future proof combo