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Lapping the CPU IHS

Lapping the IHS of our CPU’s can be easily done, with out taking to much time out of our busy life styles.


I have been overclocking CPUs, motherboards, and video cards for quite a while now. The need to drop my computer components a few more degrees has become a necessity. Especially since I like to push my CPUs, motherboards, and video cards to their absolute maximum clock speeds possible, and hold it there. The cooler we run our components the higher the overclock we can achieve, or the longer that component will last. One specific area we can tweak our cooling a bit more is lapping the IHS (Intergrated Heat Sink).

Lapping an IHS on a CPU is not as hard as most think. It does not require hours of work, and there is none of this, “You have to do this way, and only this way for perfect results.” Contrary to popular belief lapping the IHS can be done in a matter of minutes and still get a seriously high polish out of it.

I have heard of many different ways on doing this simple little task. Some are time consuming, others are so over engineered it takes this task to a whole new level. I could list the ways I have heard of, but I like to finish this guide before my great grand children start having grand children of their own.


By doing this tweak, can and will VOID the warranty you had, or did have on your CPU. We at Bjorn3D do not take any responsibility if you torch your CPU or void your warranty. As always there is a slim chance you can brick your CPU if this is NOT DONE PROPERLY.

What You will need

Lets start off on the first items that will be needed to perform the tasking of lapping the IHS. In this picture You will see six major Items. it is a good idea to purchase two of each of the sand paper grits.

  • Wet/Dry 800 grit sand paper
  • Wet/Dry 1000 grit sand paper
  • Wet/Dry 2000 grit sand paper
  • Wet/Dry 2500 grit sand paper
  • One 12×12″ glass mirror
  • One CPU that needs to be lapped (shown Here is a Core i5 750 Review can be found HERE)

This can be done on any CPU that uses an IHS. If your CPU has a small hole in the IHS DO NOT PERFORM this. (applies to the older Intel CPUs)

These are your support items that will be needed. These items are just as important as the products listed above.

  • One can of compressed air
  • One 1-2″ paint brush for dusting off
  • One bottle of Rubbing Alcohol
  • One soft cloth Terry cloth works best, one shown here is a lens cleaning cloth.

Let The Lapping Begin

Before we continue on, make sure you wipe the CPU completely down and no Thermal Paste is left on the CPU, because this may cause issues during lapping.

As we can see this is an engineering sample of the Core i5 750 CPU.

This is how to hold the CPU during the lapping process. Notice I am gripping the sides of the CPU and I am not using a lot of downward force, just use the weight of your hand.

I started to lap the IHS of the CPU with 800 grit sand paper. If you look at the sand paper you will notice small circular circles on it. I use circles in clock wise manner, then go counter clock wise. This will give me a nice cross hatch pattern on the surface of the IHS, and this in turn makes sure the surface is flattened properly.

Looking at the CPU IHS. WOW, that is definitely not flat. We can see a definite low spot, and rough machining marks on the IHS itself.

Back to lapping the IHS on the 800 grit sand paper, Notice there is no water, no oil, or any special monkied up over engineered jig to perform this task. Continue using small 2-3″ circles, clock wise then counter clock wise. No you don’t have to count the rotations.

Keep going till you see all copper on the IHS. This took me roughly 5 minutes to get the IHS to this point. Now as you look at the IHS periodically during sanding, use the paint brush on the CPU IHS side and on the back side of the CPU to clear out the excess dust.

Before going to this step make sure you dusted off the CPU IHS good prior to moving here. Just use the paint brush, then blow the CPU off with the can of air. The Rubbing Alcohol will be used last. Time for the 1000 grit sand paper stage. Do this step until your CPU IHS just starts to get a nice sheen to it. Dust off the CPU and blow it off. Also note use small circles 2-3″ and use the entire piece of sand paper while sanding.

Just a reminder on how to hold the CPU during the roughing stage (800/1000 grit sand paper is the roughing stage).

After dusting off of the CPU IHS, lets move on to the 2000 grit sand paper. Notice how I am now holding the CPU? I am going to only use the weight of my fingers. Use the same small 2-3″ circle pattern rotating clock wise to counter clock wise. Again make sure to wander all over the entire piece of sand paper.

This is what we should have now, roughly about 15 minutes after starting. Dust off the CPU, and blow it off before moving on to the next step.

On to our final grit of sand paper (2500 grit). I used the weight of my finger tips again and fallowed the same exact steps as the 2000 grit portion. Continue this step till the CPU IHS really shines. We are finally finished up.

Cleaning the CPU, just dust it off with the paint brush completely, then use the can of air to blow it off. Then get your soft rag and the Rubbing Alcohol (use a small amount on the rag), wipe the Pads (back side of the CPU) down good, then clean the entire CPU IHS down, facing and sides. MAKE SURE there is no shiny metal particles on the CPU anywhere. Then air blow the CPU down, repeat these steps a couple more times to make sure it is FULLY CLEANED.


This is the base of the CPU water block I will be using, in it we can make out the radial pattern of the lapping job I just performed on the CPU. In the CPU IHS we can see the base of the CPU water block.

Just making sure things are what they supposed to be. I did not do a full mount just yet, just stuck the CPU block on then held down on it for 30 seconds then lifted it off.

The water block I am using is the Swiftech GTZ.


Lapping the IHS is not as painful, or all that dangerous. Lapping the IHS on the Core i5 750 CPU took me roughly 20 minutes to complete. The time it will take may vary depending on how bad the IHS is, and how polished you want the IHS. If the proper procedures are taken this can be done quick fast and in a hurry.

Once again there is no more that mind set of, “It has to be done this WAY”. No matter on the way you do use, if it works for you then you do it that way. Just remember to K.I.S.S ( Keep It Stupid Simple, or Keep It Simple Stupid depending on how you want too look at it.)

By lapping the IHS of the CPU could reduce your Core temperatures even farther. If you are comfortable with the CPU remaining standard then leave it be. If you do decide to lap the IHS of the CPU please take the precautions prior to and TAKE YOUR TIME.

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  1. Lovely article, show every steps and make sense easily.

  2. This is a really old post but a tip for anyone doing this: colour the top of the CPU with a sharpie to know if you sanded away every high or low spot.

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