Thus, the calculation comes up, however, you need three conditions:
1. a motherboard whose BIOS / UEFI allows adjustment of the relevant overclocking parameters - ie a Z97 board. In my case it is a Asrock Z97 Extreme6 which proved itself very well.
2. a really good cooler, so you also for thermal overclocking has enough reserves. In my case it is a 280 water coolers (complete, pre-filled system) from Corsair, which I have installed on the casing top. A good, large intercooler does it already well - the provided in the "boxed" version cooler but certainly not that is just right for throw away. It is important in any case that the housing ventilation is designed reasonable: the best CPU cooler is not much use when he warmed previously air scoops to the processor.
3. sufficient knowledge and patience for the respective processor (each copy is a bit different) out optimal setting without compromising the expensive piece due to overheating. Best to read up a little earlier in the matter, before you start with the overclocking.
For me, the i5-4690K (all cores) running everyday with 4.6 GHz stable, with moderate VCore of 1.20 V and able-bodied temperatures: in practice-oriented full load (Video conversion) between 55 and a maximum of 60 degrees, 30 degrees in idle. Even with LinX (an unrealistic in practice extreme test) the temperature does not rise above 70 degrees in this setting - and thus even under the somewhat overcautious Manufacturer default in any case still critical. Striking this: the 4th core ("C3") is regularly around 6-8 degrees cooler than the other three cores under full load. Apparently, he is the only direct contact with the heatspreader. Too bad that you can not use by individual overclocking of individual cores that; It shows in any case that, despite the undoubted improvements to the "Devil's Canyon" opposite the Haswell predecessor thermal improvement potential is still there.
With more VCore I can rauskitzeln from my i5-4690K stable up to 4.8GHz. This, however, I have to turn up the VCore disproportionately far to more than 1.35 V, and the core temperatures then rise despite water cooling under realistic full load at 70 degrees. As the 200 MHz and no longer make the herb now more fat, I lay it down of life for the sake of content with the 4.6 GHz - for a 200-Euro-quad that is, after all, a word! Who wants to really have a lot of thermally healthy performance for an even more affordable price, is here at the right address.
Addendum 20.11.2014:
Meanwhile, I have again teased 100MHz more, the processor is running now in my everyday problems with 4.7 GHz. The necessary tests certainly took some time to complete; You have to then already see as a hobby, for saving time is nothing :-) As a note of a few with me now proven parameters (with no guarantee that the works also elsewhere!): core clock to 4.7 GHz with fixed 1:27 V core voltage. Uncore (= "Ring Bus" at Asrock also "CPU Cache Ratio" called) to 4.5 GHz at a fixed voltage 1.24 V. Spread Spectrum natural. CPU Load Line Calibration not limited to 1 or Off as often recommended but on 5 (Asrock Z97 Extreme6)! The fixed external voltage for the CPU is in my other hand on 1.9 volts - the sporadically reported trick to set this value lower, brings nothing with me. In real full load (Video conversion) go at me with these settings, the core temperatures at maximum to 62-63 degrees (water cooling). In the majority of everyday tasks with little load (surfing etc ...) the core temperatures of around 30 degrees commute - relaxed so.
