Intel Core i5-4670K - Core i5 4th Gen Haswell Quad-Core 3.4 GHz LGA 1150 84W Intel HD Graphics Desktop Processor - BX80646I54670K

Pros: This thing is lightning fast even without an overclock. It overclocks decently, but I'm perfectly satisfied with it at stock, it loads from my SSD much faster than my AMD FX-4100 @ 4.2 GHz would.

Cons: It runs pretty warm. This thing idles hotter than my AMD was at 100% load. It does have a higher thermal limit though, but I don't like having a space heater in my house during the summer.

Overall Review: This is my first Intel CPU I've ever bought, outside of some older store-bought computers that I've had long ago. I didn't realize the difference in performance between AMD and Intel. I know comparing a ~$100 at release Bulldozer to a ~$200 newer Haswell isn't a fair comparison but it's definitely worth it for the performance gain.

Pros: Low power consumption. Will play pretty much any game with its proverbial hands tied behind its back, all day. The onboard voltage regulator means you are guaranteed to get high quality voltage regulation regardless of motherboard.

Cons: A lot of variation in silicon quality. I really need to push the voltages (~1.267V) to get it to overclock past 4.2 GHz. Uncomfortable with how high I had to push it I decided to back down to 4.1. Others have gotten really high overclocks without breaking 1.260V.

Some PSUs don't play well with certain low power sleep functions of Haswell. Disabling it is a bummer (I didn't have to), but really it isn't an issue with the processor, rather Intel's failure to alert the consumer and power supply manufacturers properly.

The onboard voltage regulator, coupled with, among many things, TIM rather than solder for the IHS to die heat transfer, means this chip can run a bit hot, really limiting overclocking. Gone are the days of the 2500k, sadly.

Overall Review: This processor needs to be overclocked. I recommend, if you aren't a huge overclocker, to aim for 3.9GHz. Every half decent after market heat sink should do it just fine and every 4670k should hit it no problem. That allows all 4 cores to hit turbo frequency at the same time rather than having Turbo Boost decreasing one or two.