It is also thought that it will be able to surpass 5GHz using air cooling. Chinese tech site EXP Review believes that the upcoming Intel Devil's Canyon chips could surpass 5GHz using just air cooling techniques. An Intel PDF has been unearthed which is thought to detail the Core i7-4790K and Core i5-4690K chips and they represent much more of an uplift in clock speeds compared to the Haswell refresh we have seen previously.

You can see the slide below detailing the two first Devil's Canyon chips (it's only just readable so click it to enlarge to full size).