All You Need To Know About Haswell Overclocking - Intel® Core™ i5 4670K & i7 4770K

Intel® Core™ i5 4670K & i7 4770K - Haswell 22nm

Page created for inserting and sharing your overclocking results; not an overclocking help thread for beginners

Technical Specifications

Intel Core i5 4670K processor:

  • 4 Core, 4 Thread
  • Frequency: 3.4GHz (3.8GHz maximum with Turbo)
  • Multiplier: x34 (unlocked)
  • Cache L3: 6MB
  • Integrated graphics: Intel HD 4600 (350-1200MHz)
  • TDP Maximum: 84W
  • Maximum amount of RAM supported: 32GB
  • Supported RAM frequencies: 1333-2600MHz

Intel Core i7 4770K processor:

  • 4 Core, 8 Thread
  • Frequency: 3.5GHz (3.9GHz maximum with Turbo)
  • Multiplier: x35 (unlocked)
  • Cache L3: 8MB
  • Integrated graphics: Intel HD 4600 (350-1200MHz)
  • TDP Maximum: 84W
  • Maximum amount of RAM supported: 32GB
  • Supported RAM frequencies: 1333-2600MHz


Fourth generation i5 and i7 processors may be considered less susceptible to high temperatures, particularly in the eyes of former Core (2) Duo or Quad processors owners. However, it is advisable not to exceed 80°C during a stress test such as LinX or Prime95 in order not to risk damaging the processor in the long run. The TJMax of these processors is 100°: if the sensors inside the CPU detect temperatures higher than this, the overheating protection system will intervene, shutting down the computer immediately. This function is easily disabled through the BIOS of most motherboards, but it is strongly recommended to keep it active.

In some cases the temperatures may be unjustifiably high: often, there are also large differences between the values recorded by the different cores. The reason for this is that, unlike the previous generation of Core processors, where the die was ihs soldered, in this case common thermal paste is used, and sometimes it is spread well, some other is poorly distributed or in excessive quantities. It is therefore possible to try to “uncover” the processor, revealing the die, to change thermal paste, as explained in the eighth post of this discussion, which Raven kindly reported, but which was written by the user Giustaf (Ivy Bridge):…82&postcount=8

Haswell, razor blade/cutter method (riskier as far as we can tell):

bitten method, wood and hammer:


I’ll start immediately by saying that the information below is to be considered a personal advice of who wrote the thread (on the other hand in overclocking there is nothing certain, every CPU is to be discovered and therefore the advice is often more useful than a thousand technical data). Here is a brief summary of the main voltages adjustable by the BIOS, with related stock values set by Intel:

  • VCC (or VCore or CPU) Voltage: This is the processor voltage. A moderate increase can help to find stability at high frequencies, but temperatures will increase, so it is better to arm yourself with a little patience and, through stability tests, find and use the lowest value able to guarantee the correct functioning of the CPU at a certain frequency. In general, temperature permitting, 1.35V can be considered the maximum limit for a daily use overclock with quality air-cooled or pre-assembled liquid kits. In case of “hard and pure” liquid systems, with large radiators, waterblocks and quality pumps and pipes of a certain diameter, it is possible to go even further.

  • DRAM (or DIMM, or DDQ) Voltage : 1.50 - 1.65 V Increasing the supply voltage of the RAM modules, similarly to the VCC, helps to maintain the operating stability of your ram kit at high frequencies (or low timings). In these new CPUs, unlike Ivy, you can dare more in terms of voltage (maximum allowed seems to be even higher than 1.65V, with proper systems you can even exceed 2V on the ram).

Reading the Batch

We can get to know the location, year, week and batch of our CPU’s production, simply by looking at the code on the CPU’s IHS or a label on the box as a seal.

  • 1st Number or letter = place of construction 0 = San jose, Costa Rica 1 = Cavite, Philippines 3 = San Jose, Costa Rica 6 = Chandler, Arizona 7 = Cavite, Philippines 8 = Leixlip, Ireland 9 = Penang, Malaysia L = Penang, Malaysia Q = Penang, Malaysia R = Manila, Philippines Y = Leixlip, Ireland

  • 2nd Number = Year of production (1 for 2011, 2 for 2012, 3 for 2013).

  • 3rd and 4th Number = week of production.

  • From 5th to 8th Value = the batch number.

For example, a processor with batch L313B428, like the mmio, will have been produced in Malaysia in the 13th week of 2013, and belongs to batch B428.

Overclocking Risks and Intel Warranty

Overclocking is a practice that violates the terms of Intel’s standard warranty. However, there is a specific warranty option for overclockers called Tuning Plan, which for a small amount ($25 for i5 and i7 Haswell CPUs) allows the replacement of the damaged CPU in overclocking, and is in addition to the normal 3-year warranty valid for all Boxed processors. This warranty is valid for one replacement only, and more information about it can be found on the Manufacturer’s official page:


  • The two processors in the thread seem practically the same: being both quad cores, what should lead me to prefer the 4770K, which costs 100€ more, apart from the 100MHz and the 2MB of L3 cache difference? It’s true, both processors are quad cores, but the main distinction between the i5 and the more expensive i7 is the presence, only in the latter, of HyperThreading: the physical cores (i.e. physically installed inside the DIE of the processor) are always four, but the logical ones, recognized and exploited by the operating system, are eight. It is wrong to think that this leads to a doubling of the actual performance, however with programs that support multithreading, as well as multitasking, there are considerable increases in processing speed. Since this is a discussion focused on overclocking, I think it is correct to specify that activating Hyperthreading could result in a (slight) decrease in the processor’s oc potential. This function, however, is easily deactivated through the BIOS.

  • What meaning does Intel give to the “K” after the number that identifies the processor model? Is it somehow related to overclocking potential? The final “K” denotes the possibility of overclocking the processor by raising the multiplier at will, beyond the manufacturer’s specifications. In this generation of processors, acting on the multiplier is the only way to obtain frequencies significantly higher than those declared by Intel, because it is no longer possible (unlike the old Core 2 Duo and Quad, as well as the Pentium) to operate on the bus frequency, if not in a minimal way, to increase the overall frequency of the processor. However, it is not recommended to modify the BCLK: since the Memory Controller, as well as the GPU and other components we would have expected on a motherboard are integrated in the DIE of the processor, it can be risky to touch the settings related to this bus.

  • Where is the Northbridge on the motherboard? Does its absence make the purchase of an expensive motherboard unnecessary for overclocking? The Northbridge doesn’t exist anymore: most of its functions have been moved within the CPU itself; some of them are the responsibility of the Southbridge (in charge, as always, of managing the expansion ports). This, in part, leads to a lesser influence of the motherboard on overclocking results, but it is wrong to say that it doesn’t matter anymore. The power phases of the processor, in fact, are present on the motherboard, and therefore the quality of this component determines the stability of the voltages, which have (obviously) heavy influences on the overclocking possibilities. Not to be underestimated is also the BIOS configurability: more advanced and therefore expensive boards offer a greater amount of parameters and more freedom in their configurations.

  • My RAM kit is guaranteed to work at 1.65V: there is no risk if I use my banks at this voltage, right? No problem in this case, unlike Ivy, Haswell likes ram voltages even higher than 1.65V.

  • How can I control the Batch on my CPU? The batch number can be found on both the CPU ihs and the processor box label. More information about the information contained in the batch code can be found in the first post.

  • What is the difference between a “Boxed” and a “Tray” processor? Boxed” processors have a complete package, containing the heat sink, instead if you buy a “Tray” processor you won’t get any accessories, just the CPU. The warranty also varies: three years for Boxed processors, only one year for Tray processors.

  • With which motherboards can I use the potential of my “K” series processor? At the moment, for overclocking via multiplier, it is necessary to use a motherboard with Z87 chipset (born specifically for this generation of processors), or H87 or B85 (for which you need a BIOS unlock that many manufacturers have already released). Beware that Intel on will most likely allow more, in the next releases of H87, B85, B81 bios, to use the unlocked K CPU multiplier… so you may not be able to overclock the CPUs with a mobo that has these chipsets!

Overclocking Utilities

I will as far as possible avoid direct links to downloads, because they would risk becoming inactive within a short time, and would require continuous adjustments for each update.

Temperature monitoring

Real Temp HWMonitor Core Temp

Characteristics detection


Stability Tests

LinX (in this case I’ll make an exception: THIS is the direct link to the first release that supports AVX instructions in 3rd generation Core i5 and i7 processors, but not yet compatible with Haswell’s AVX 2)

LinX 0.6.5 AV compatible

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