I5-670vrs i7 860

thats easy, 860, its faster and cheaper, only good thing about the 670 is the 32 nm.

really because the we site i found these at thei5 was 410 cheaper

http://www.newegg.com/Product/Product.aspx?Item=N82E168...

http://www.newegg.com/Product/Product.aspx?Item=N82E168...

according to my amazing math skills, the 860 is 20$ cheaper  

If your applications are multi core capable, then the i7-860 will be the winner.
If your tasks tend to be single or dual core intensive, then the i5-670 would be better.

But... consider the i5-660, it is about $90 cheaper, and only one multiplier slower. I have been testing one for a friend who does scientific calculations, and it is a screamer. It does 2m superpi almost as fast as my overclocked i7-920.

As the 860 has a very good turbo mode, with 2 cores active the frequency jumps to 3.33GHz according to reviews I've seen, so even if you only used apps optimised for dualcore *at the moment*, you'd still get great performance - so for roughly the same price it's a no-brainer to get the 860 as you get a full quad core chip.

Does turbo mode kick in if you overclock?