Overclocking with Haswell processorsUpdated B-Clock tuning ratios brings an overclocking experience consistent with the current high end desktop platforms (X79 on LGA2011) to the 4th Gen Intel Core processors mainstream platform. We've mentioned at the start of this article already, if you are planning to do some overclocking with a Haswell based processor, you are so much better off with a K model processor. The downside, Intel charges you another 30 bucks for that these days. Why K versions you ask? Well, the default non-K processors will be much harder to overclock. With Nehalem/Clarkdale (last generation Core i3/i5/i7) you pretty much take your base clock of 133 MHz and apply say a default multiplier of 25, that would be your 3.33 GHz processor. That base clock was capable of going so much higher, 150, 186 and when tweaked right, even over 200 MHz. So if you were able to apply a fictive 175 MHz on your base clock, you could multiply it with the limited 25 multiplier. That would get you 4375 MHz.
The new technology however has an embedded GPU / video processor merged into the very same processor die running over the same bus sharing the same L3 cache memory, things get increasingly complicated in matters of tweaking. But please do get a 30 USD more expensive K version and in the BIOS you'll have much better tweaking options. With a proper motherboard you can now set a multiplier per core.