So the fx 6100 is better than 2600k/2700k/3770k?
No, about 2/3rds of the performance spread over more cores. Less performance per core = less performance overall at a lot of times. It would be nice if a lot of programs were multithreaded but we are still a long ways off from that day. You seem kinda indecisive though, are you sure that you are purchasing what you want or are you purchasing what you think you want?
The reason I ask is that I too recently "upgraded" to a 2600k system. Unfortunately, I purchased an MSI H67 chipset motherboard - as MSI stated it could overclock. Unfortunately, they were misleading since you cannot overclock the cpu - only integrated graphics, which I am not about to use. Technically, the chipset would overclock the CPU just aswell as the Z68 but Intel locked that feature out because, stated simply, Intel wants to be scumbags in that area. But, this motherboard was $45 early this year whereas a z68 board would have been over $100. Performance with the 2600k is not what I imagined - reason being is that I came from an AMD Athlon II x4 620 which, when overclocked to 3.8 GHz was exactly half as fast as the 2600k. (Except in floating point math where the AMD chip actually made the 2600k look like a Pentium 4 lol) The hyperthreading of the i7 series is a joke, just as it was with Pentium 4's, Windows 7 acts like those "cores" have the Ebola virus and doesn't even use them unless it has to.
I would not want to overclock this chip unless I was doing some sort of insanely demanding task every day (ie: not web surfing or gaming, I was stupid to upgrade techinically, and very stupid to spend the extra hundred on an i7 over an i5). I originally almost bought into the Socket 2011 platform because I was almost sold on the quad channel ram idea... Until I realized that nothing I could do with my computer would require more bandwidth at the current moment than dual channel ddr3-1333 offers.
If I did it all again I would get a $200 i5 if I didn't already have the old AMD x4. But as was, that $75 AMD chip is a much better value than a $200 i5 and only a slight downgrade, unnoticeable to most humans. But I'm not a big fan of either AMD or Intel products these days, they both have so annoying weaknesses. Get a decent CPU and just spend the few extra hundred on GPU power dude. I am running dual ATI 4890's and that's my bottleneck, GPU power is where it's at!