i7-4610m would be the end of the line for that system.  
I want to install a new CPU into my dell latitude e6440 laptop, I found one that seems really good I just want to know if I would have any issues using it i7-4940MX CPU I currently use a i5-4310M CPU  CPU-Upgrade: Intel Core i7-4940MX CPU
E6440 laptop CPU upgrade