Which cpu is faster?

The AMD FX-4 4170 is actually the faster CPU if you are talking about games. Simply look at the difference in clockspeed.

- The vast majority of games only use 2 cores.
- The number of games that can actually use 4 core is tiny in comparison to games that only use 2 core. But if you are looking to play specific games that can take advantage of 4 cores then you will be able to fully utilize a quad core CPU.
- No game uses more than 4 cores (to the best of my knowledge) so any CPU with more than 4 cores will have cores that will be idling all the time. Unless you are running other CPU intensive programs in the background.