Preface to OC:

Before you start overclocking it is important to know what type of memory and cooling you have, first you want to OC the CPU and then the memory separately as to not cause issues which are harder to pinpoint. After you change each setting you should use a stability test such as Prime95 or IBT to test for stability before going up another notch.

Step #1 Overclocking the CPU Frequency:

On Ivy Bridge overclocking is done through the CPU Multiplier on a “K” series SKU like the 3770K and 3570K and the multiplier is multiplied by the base clock. When you overclock the base clock you are overclocking the DMI and PCI-E busses as well, so you might damage or corrupt the devices hooked up to these busses such as your HDDs/SSDs and GPUs on the PCI-E bus.

CPU Frequency = CPU Multiplier X Base Clock

Memory Frequency = Memory Multiplier x Base Clock

That means if you increase base clock you increase both memory and CPU frequencies, you also increase the iGPU’s frequency as well. However with Ivy Bridge you shouldn’t be increasing the Base Clock for Air/H2O overclocking as BCLK OC takes a toll on everything on the PCI-E bus including your GPUs and your SSD/HDDs, so it is pretty much reserved for benching with colder temperatures. Don’t worry about increasing BCLK for memory speeds as there are enough memory multipliers with Ivy bridge/Z77 so you can always find the speed you want unlike with Sandy Bridge. However you can increase the BCLK slightly for high memory OCes where certain multipliers are better than others.

What I shoot for is a stable 4.6-5GHz OC with Ivy Bridge, such as something like this:



The temperatures are much better than that of the 5GHz shown earlier, topping out around 90C under full load, also the wPrime score, while the benchmark and OC aren’t tweaked, shows it being faster at this speed as the temperatures are lower and the CPU isn’t throttling.

With Ivy Bridge, you want to slowly increase the VCore as temperatures will hurt your max OC much more than voltage can stabilize it. I would go one multiplier at a time sticking to my voltage ranges in the graph below. If you end up with too much heat then the logical thing would be to decrease the voltage, however at this point you can try to decrease the CPU PLL, and if that doesn’t help much you can always decrease the VTT and System Agent (IMC) to levels where they are lower but still remain stable. When I was messing around with LN2 I could validate 5 GHz with less volts than my CPU needed at stock frequency, that is how much heat has an impact on frequency. However I do not want to show that shot as people might not always read stuff, but 5 GHz at 1.2v isn’t impossible at -190C.

Below is a chart that shows the optimal voltage settings which you should aim to better:



You should try to fall under these voltage ranges or slightly above to stabilize your OC, these are the recommended voltages per frequency, however the CPU I used is very good it seems, so you might need more voltage than I did.



Above you can see where it says CPU/PCIe Base Clock as well as the CPU Clock Ratio which is the CPU Multiplier and the System Memory Multiplier. With just increasing the multiplier you can increase the clock speeds of the CPU up to about 4.2 GHz with 42x100.00. If you want a set 100 MHz even base clock it is best to set the base clock to 100.00. SVID will stabilize the CPU to about 4.2 GHz but not beyond that, so you will need voltage increase above 4.2 GHz.

If you want the best results you should disable power saving options like I have below, however if you want the CPU frequency to drop under idle conditions, you should leave them enabled. You should also leave them enabled if you will use DVID Voltage offset instead of fixed voltage. If you decide to leave on power saving options, make sure that you increase the turbo current limits for the CPU within the turbo settings list to 200A and 300W to totally maximize Intel Turbo limits; however this might not be needed.



Any overclocks above 42x will probably require VCore increase, and this can be done through the CPU Voltage menu:



You will also want to set LLC which is under the 3D power menu, the LLC should be set to Turbo for a slight droop, or Extreme for no droop at all. The LLC on these boards is rock solid, what you set is what you get, and nothing other than that. If you want you can also mess with the other PWM settings, but that shouldn’t be needed as Ivy Bridge doesn’t pull enough power to warrant those changes under air cooling. I recommend a slight drop of voltage under load, this might help with temperatures.

Page 1 - Introduction	Page 6 - Step 3: OC-Profiles
Page 2 - Ivy Bridge Basics	Page 7 - Ivy Bridge and LN2
Page 3 - 22 Nanometer and Maths	Page 8 - Ivy Bridge LN2 Memory Overclocking
Page 4 - Step 1: Ivy Bridge CPU Overclocking	Page 9 - Ivy Bridge BCLK Overclocking
Page 5 - Step 2: Ivy Bridge Memory Overclocking

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