New processor for Dell prebuilt

[Zada]

Let's say that I plan to upgrade to a new processor because my Pentium G2020 is bottlenecking my GT1030, would it be more advisable to get an i3 3220 at 55w or an i5 3550s at 65w? I don't understand the math of the entire power consumption thing and I need some advice. I'm also concerned at the "boost" clock of the i5 3550s cos if you push the cpu it'll take more power right? If so is it more advisable to get the i3 instead and forgo the potential performance increase? 

 

Specs:

Pentium G2020

Zotac GT1030 LP

6gb DDR3 Ram

1 120gb ssd

1 7.2rpm WD blue 500gb hdd

220w Dell prebuilt psu

 

Choices: Upgrade to a i5 3550s or a i3 3220