Intel Core i7 4770K  vs i5 4670K 

yes, you*re right. these automated comparisons rly suck. everyone like the others here looks only at overall benchmarks. which is 100% of pc-uptime video encoding (not DEcoding), winrar-packing (not DEpacking) or other stuff normal pc-users never do. and everybody who only spends 200,-$ for a gpu does'nt know anything about gaming :)

The difference is 2mb l3 cache and hyperthreading.

The only difference is the i7 Is hyperthreaded, if you have an AMD GPU I highly advise getting the I7 Because the AMD GPUS don't have onboard Physx so it has to be done by the CPU, and it is a multithreaded task.

This is false. Benchmarks show no difference between an i5 4670k in gaming compared to an i7 4770k. The if 4670k actually outperforms it at times in major titles.

I installed the streamer and I can't get it to work (from what i can tell it needs a video capture card). I can however tell you that crysis 3 uses 65% CPU on all 4 cores @ 4.7 ghz and 99% of my gtx 680 on all high settings at 30fps on the beginning mission. So on games like crysis 3 and perhaps (because I have not tried played it myself) battlefield 4 it might be worth going with the 4770k. But on any other game you will be fine with a 4670k.

Sure, np.

Anything that can use up all available CPU power in order to speed up its function will make use of hyperthreading. The thing with twitch tv is its very situational. For example if I play mass effect 3 on absolute highest settings at 2560x1440 I only utilize one of my cores at 80%. Which means I have the full power of the remaining 3 cores on the 4670k. I have heard that battlefield 4 is a very CPU intensive game when it comes to multiplayer and is one of the few games that can utilize all 8 cores and make good use of hyperthreading on intel i7's. If you use twitchtv now my suggestion would be to play a game that you can easily run then begin to twitch it and use an on screen display or LCD display on the keyboard to take notice of how much CPU power twitch is using itself. Although I have not used twitchtv myself I would doubt that it would require a ridiculous amount of power to use as that would make its practical use garbage. It has probably been optimized to use 1 core very well and so you should have no issues with a 4670k. If you have time and can wait for me to load up say crysis 3 and play around with twitch I could get back to you with a precise answer.

"Video encoding, editing etc" Explain the "etc" please? I'm trying to decide between i5 and i7. Would the i7 be better for streaming on Twitch.tv? Does hyperthreading affect streaming? Essentially, it's real-time video rendering isn't it?

what games will you play?

Sorry hyper threading means nothing for gaming and won't for years to come. If it's just gaming 4670k. Video encoding, editing etc 4770k. I own both And have benchmarked both and they are identical in all benchmarks except in games or benchmarks that use physx on the CPU which is an obvious multithreaded dependent thing.

not true. rendering each frame relies on action from the CPU. as games become more complex, or videocards become more powerful, the CPU matters more than ever before. the 4770K can literally squeeze out 20% more FPS with the same videocard, than say, AMD's best CPU. It's not too much about what happens in a second, but rather what happens in milliseconds and nanoseconds, and a faster PC is obviously going to do more in these short time frames. for example, in order to get 60FPS, your PC must draw a frame every 16 milliseconds. this also means your CPU must do its tasks the frame requires within those 16 milliseconds, or a frame is delayed. So since the GPU relies on many CPU tasks, even GPU dependent games still benefit greatly from a strong CPU. 160fps vs 190fps might not seem like much of a difference to worry about, until in the future when it's 60fps vs 40fps with newer games. I don't know about you, but if I spend $200+ on a GPU, I want it to be able to squeeze out as much FPS as possible for as long as possible, and a good CPU will ensure that. It is a difficult choice between 4vs8 threads with the price difference being nearly 100 dollars, especially since hyperthreading doesn't scale too well, but it still does offer a somewhat substantial boost.

Im building a pc for gaming and want to get no lower than 70fps. 4670k+gtx 780 ghz edition will be my next purchase.

If you look for the "value for money" factor i5 4670k is one of the best. But i7 is i7! For a gaming pc the 70-80% of work is made on the gpu, so you don't have a serious reason to buy an i7 for an absolut gaming pc. Save these money and buy a better gpu like 780 or 780Ti.