Is it worth to upgrade G620 to i5-3350p? or more suggestions

[larceny]

CURRENT SETTINGS:
cpu: G620
ram: 8g 1333 (cause of limit of G620, down to 1066)
display card: GT220
hard drive: 2T 7200pm


MAIN PURPOSE
Mobile App Developing
Java EE programming
Audio and Video Editing
3D Modeling (no heavy rendering)

by the way, no heavy 3d gamming

CURRENT ISSUE
upgrade the machine.

The first idea came to my mind is to upgrade the cpu. Since I have a discrete display card, so my focus is on i5-3350p. Considering most of my work-related software needs massive I/O operations, I also wanna add a SSD Drive to store the Windows system and mostly used software.

Question, is the upgrade of G620 to i5-3350p, will bring my work obvious efficiency improvement? If there will only be 2-3 seconds change, I can save that 100 bucks.

Thank you in advance.