4770k vs 4670k

I'm just finishing up my first build, all I have left to get is the processor.  I will be using it for gaming, some CAD for school, and photo editing.  How much of a difference will the i7 really make?  Is it really worth the 100$ more?  Here is my build so far http://ca.pcpartpicker.com/p/1ojT3.

Hello there! For gaming, CAD, and photo editing, the 4670K will be enough! The extra threads that the 470K has will not improve performance in those applications. It can help if you are going to be making extremely large/complex CAD models, but the performance increase will probably not be significant and not worth the extra $100. 

The only reason to get a 4770K is if you are going to be doing video editing or if you will be running any computational programs. 

Get the 4670K, you will be happy with it! 

-fishymamba Intel Response Team http://bit.ly/IntelRally

To be honest, not much at all. When you get to those high end expensive processors the computing power to dollar nose dives. You'll get more than enough performance from the I5, in all honesty there's a good chance that you'll actually never even max that chip out. The better idea would have been to save that extra hundred and get an even better graphics card. 

Thank you to both of you!  I suspected that the i5 would be the better choice, but I wanted a second opinion.  I'll definitely be going with the i5.  Thanks again!

Thanks for your help!  I will be going with the i5.  In terms of the video card it's "borrowed" from a friend, which is why I went  with it, I may upgrade in the future or add another card for sli.