Yes, that CPU will work with your system.  Adding RAM to the 8G max would be another good idea.

Unless you know the CPU is holding the system back, if you have to choose one or the other, the memory will make a greater difference than the CPU will -- particularly if the system is running a conventional spinning hard drive.

@ejn63​ i mean the cpu is single core, dual core will make huge difference since my cpu always bottle up to 100% 

Ram wise i am using linux so it uses about 200mb from ram