what's the best modern cpu for Europa Barbarorum II

i want to build a new pc able to run old and new total war series with smoothly and best performance , my laptop is lenovo y510p
i7 cpu 2.4 GHZ
cpg 755m ram 8 gb
iam stuck with this laptop iam not able to run attila or rome 2 on ultra or high setting ,at the same time iam not able also to run rome 1 or medieval 2
any suggestion please ?

Any processor with more then 3GHz per core will run M2TW fine (doesn't apply to R2 or Attila), very likely even at highest specs. 2.4GHz simply won't cut it due to single core use of M2TW.