You Guys are Awesome..!!! Lets get to the topic.

Cache Size: It is inbuilt or build inside the processor itself. So when computer finds same data is used again and again its stores it in the cache. So computer does not have to read the data from Hard disk again and again.
Remember the connection in below order, see below pictorial representation:


CPU <--> Cache <--> RAM <--> Hard disk



RAM ( It will also store the repeated data) will minimize the interaction between Hard disk to CPU while Cache will minimize the interaction between RAM and CPU.

In i3s Cache range from 3 MB to 4 MB
All i5s cache will have 6MB

So in case of Cache i5 is the winner.


Where as In i7 cache range from 8MB to 20MB. So i7 is ultimate winner.