**Disclaimer: Overvolting/overclocking can/may reduce the life expectancy of a part. Overclocking your CPU technically voids your Intel CPU warranty. Use a quality aftermarket CPU cooler (mentioned in guide).**

Hi there. This guide is a simple guide meant to just get you there. The guide is as concise as possible and the steps as clear as possible for new people. I don’t want to overcomplicate the thought process and confuse new people. Please understand it is a simple guide for those wanting a medium overclock. It is not meant to get you much past 4.5Ghz If you have questions, ask in General Hardware “Trying to overclock 2X00K”, or ask in Intel CPUs, or ask in this thread. Thanks. 

*Important note: This guide was written before the current 3570K and 3770K CPUs. You should buy these instead now, as they replace the 2500 and 2600/700K.
1:Before we begin:
You have:
*a 2500K, 2600K, 2700K CPU

*A Z77Z68 or P67 chipset motherboard.

*You know your ram timings (look at the box, the ram, or the ad for where you bought them. (Example, 9 9 9 28 1600Mhz 1.5V or 7 7 7 24 1.65V))

*You have an aftermarket cooler. The coolermaster 212+ is sufficient for this overclock across all three K sku 1155 CPUs . The 600 and 700, with more cache, require a higher tier cooler at the voltages needed when going to a higher overclock. If you have a 2500K you will be able to reach for the sky with the 212+. For 2600K or 2700K I recommend something like Thermalright’s Archon if you wish to aim for the sky.

*You will need to download stressing and monitoring software mentioned in this article. It is all free and a link to said software is provided to make things easier.

*Please read the entire post to make sure you didn’t miss anything 

2: 4.5Ghz Guide bios settings :

*Note about some boards. As you can see in this thread http://www.overclockers.com/forums/s…d.php?t=692224 certain boards require that you make changes to the ‘max power duration limit’ and/or disable max power duration limit to prevent throttling

*Note about different mfgs bios– They are not all the same, for instance, to change the turbo ratio (to 45 to get 4500Mhz) on an ASUS board you go to Ai tuner. Other boards from other mfgs are different

Let’s begin:

** Restart/start your computer, Enter the bios, usually by repeatedly pressing Delete. Overclock in your bios. Do not use a windows based overclocker as the results do not tend to be as good.***

1 Set overclock tuner, sometimes called differently, to manual.

2 Set max turbo ratio to 45. Enter your ram section. Enter the timings (your ram timings for the ram you bought. ie, 7 7 7 24 or 9 9 9 28 etc) . Leave the rest of the ‘sub timings’ on ‘auto’ Leave the RAM speed at AUTO unless it is miss reading (ie you have 1600 reading as 1333). In that case enter the correct number (ie 1600)

3 Go to the voltage section. Set CPU and RAM to manual. Leave the rest of the voltages AUTO. The RAM should be set to the ‘sticker voltage’, ie, 1.5v. The CPU, set to 1.35V

4 Find Load Line Calibration, or LLC. Set it to 50%. If it is in levels, 5/10 or 3/5.

5 Go to CPU features turn off C5 C1 and EIST / Speedstep . Some CPUs/boards will still hold this OC with speedstep left on. I suggest you turn it off for now. Also turn off any power saving features. You may also disable virtualization if you will never use it. Note that, SOME CPUS may require CPU PLL overvoltage to be turned on to hit 4.5Ghz. It is unlikely.

6 (optional) Go to onboard devices and shut off anything you arent using (USB3/Firewire controllers, extra LAN controllers, Extra SATA controllers)

Please note:
*Less than 5% of CPUs according to a published test by Asus will need more than 1.35V or refuse 4.5Ghz altogether. 80% need LESS than 1.35. 

Save changes. Exit, restart and enter windows and now run stability tests to make sure it went ok.

Note: (If your PC will not boot now, remove the motherboard battery for a minute to clear CMOS and restore stock settings. Or press the clear CMOS button if your motherboard has one. On some boards the MemOK button doubles as this check your manual.
If it will boot but not enter windows, restore optimal defaults in bios, make a post in Intel CPU to ask what
is wrong. This happens. 5% of CPUs will not take 4.5Ghz according to ASUS’ in house testing. All is not lost and yours may take 4.4

3:Test for Stability: 

First we want to run P95 BLEND. 
http://files.extremeoverclocking.com/file.php?f=205 <Download the 64 bit version of Prime 95.
If you have a 32 bit Win 7 then install the 32 bit version. Run ‘blend mode’

Feel free to do other meanial tasks while it runs. A solid overclock ought to allow this. Listen to music or read and write in forums. Do not play games, render video, fold, or anything intensive though.
Prime 95 should be run for about 3 hours. 6 would be ideal though. I feel 12 is unnecessary. At this point, you’re pretty well guaranteed a stable system. 

Use the following monitoring software to keep an eye on your CPU temperatures while you run your stress test (blend)


HWMon will monitor your CPU voltage. Make sure your voltage is holding around 1.35 or you may need to reset load line calibration to a higher or lower number depending on your brand and board.

Post about your results with screenshots so we can tell you everything is ok.

To be extra certain of stability 

Run Intel Burn Test 
http://downloads.guru3d.com/IntelBur…load-2047.html DL link is at bottom. Not side.
5 passes. Just set to maximum, let it run and do its thing, and if it finishes 5 passes, your OC is in all likelihood a very stable one.

Know what your temperatures are and what’s safe. 
A cold cpu is a happy one. Monitor your CPU temperatures. We always take the hottest ‘core’ as your max core temp. Never the lowest.
in my opinion, as well as that of the HWmon software, and Intel specs, these are the ranges for sandybridge.
Green is perfectly safe. Yellow is a little warm but ok. Red is too hot. purple is dangerous. The cpu will throttle and prevent itself from dying from overheating, but you still must keep a good temperature.

0-70 Safe
70-80 Safe. Attempt to lower the temperature
80-90 Approaching unsafe levels
90-100 Dangerously hot

If your CPU ever gets into the 80s, IMO, it’s getting too warm. It is ok to allow 80-82 for the 15 minutes IBT takes to run. As a general temperature for any period of time, however, it is overly high. The idea is to have a Sandybridge system which rarely if ever exceeds 70 in normal use. It shouldn’t exceed 80 in normal use. If you EVER hit 90, stop whatever you’re doing and let the cpu cool to idle IMMEDIATELY. You should not allow the CPU to exceed 85 IMO.

I always try to stay under 70 max (use, ie gaming, etc) temp when overclocked. Please note that your actual use temps (ie, playing a game) will be about 5 degrees less than prime95 and 10-15 degrees less than Intel Burn Test. For example, I get about 55-65 gaming, 70-75 in prime, and 80 in IBT. Leave CPUID HWMon open while you game for an hour. Then go see what your max temps were. Good way to find out. Tells you your max GPU temps too.




Here’s what I got after playing Rise of Flight for about 1/2 hour. See my max CPU core temperature was 55C.
As you can see, even though my system hits 80 in Intel Burn Test, an average stress game doesn’t even hit 60. Some more intensive games give me
a load of 65 but I never hit 70 gaming.

Now you’re good to go. Congratulations  Go compute !

In closing:
You should now have a stable 4500Mhz cpu. If you want to tweak more and you wish to stay at 4.5Ghz, you can likely run 4.5ghz at less than 1.35v. Keep lowering the voltage (1.345, 1.34, 1.33) untill it will not blend. Then bump it back up 1. While binning I met a 2600K that would take 4500Mhz at a mere 1.3V. Others have reported success at even at 1.27! This is rare. This is called a ‘good bin chip’. Not all CPUs are identical in how they will overclock. A good bin chip will go higher on less voltage. As they are not all identical in their ability to take overclocks it is not possible to guarantee what you’re going to get until you test for yourself.

Thanks to Pablo Escobar for writing and submitting this article!


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