Possible 7010 processor upgrade

Question 1

I have an Optiplex 7010 with intel i3-2120 processor which, according to intel specifications, runs at (base) frequency 3.3 Ghz.

I am considering upgrading to an i7-3770s processor which, according to intel specifications, runs at base frequency 3.1 Ghz and can turbo boost to 3.9 Ghz.

(Interesting that the manual for the Optiplex 7010 states that the frequency of i7-3770s is 3.4Ghz. Where did they pull that from?)

As the base frequency of the i3-2120 is FASTER than the base frequency of the i7-3770s, would it be better to stick with the i3 processor? 

What is the point in upgrading to a ‘faster’ processor if it is only faster when it turbos?

Question 2

The computer is using Win 7, 64 bit.

My bios is currently sitting at version A23. Is it worthwhile updating the bios to the latest A29 version?. I am currently at version A23. Or should I go to another version like A25 or something?

Question 3

Can anyone recommend a piece of freeware that will test the performance of my computer, that I might run this before and after CPU upgrade to confirm a performance improvement?