BIOS and Overclocking with Haswell processors

Overclocking with Haswell processors

Updated 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.

The (easy) procedure is as follows:

1. Leave base-clock for what it is right now
2. If optional, increase the TDP limit of your processor to 200~250 Watts
3. With a 4770K change Turbo multiplier to 44 initially and gradually work your way upwards.
4. Increase CPU voltage, though setting AUTO might work fine, we think 1.3V on this motherboard is a sweet spot.
5. Make sure your processor is properly cooled with enthusiast grade heatpipe cooling or liquid cooling
6. Save and Exit BIOS / UEFI

Intel has built a great looking UEFI BIOS alright: 

With this tweak, once the processor gets a kick in the proverbial nuts, it can turbo any or all cores towards that multiplier of 46-47 times that 100 MHz baseclock frequency, that's a 4600-4700 MHz configuration, this is all set up in less than a minute.

This overclock will be integrated into the test sessions, we had a hard time getting over 4600 MHz stable with the reference motherboard and air cooling. We settled at 4600 MHz and even then it throttled done every now and then. Results with motherboards from Gigabyte, ASUS and MSI show similar clock-frequencies, yet more stable (as our pending articles will show you).