Lapping the IHS on a CPU

There are many ways we can do to help reduce the overall temperatures of our CPU’s in our computer systems. The simplest ways we can reduce the overall temperature of our CPU’s is by changing out the cooler. A lot of times this works out perfectly, but if you are a serious overclocker, like myself, dropping the temperatures on the CPU takes on a whole new meaning. Lapping just the heatsink doe snot always work because the face of the IHS of the CPU is not always perfectly flat. So we are forced to make radical changes to our CPU’s to ensure that they are flat as possible for our CPU coolers to work properly. So I bring forth a CPU IHS lapping guide, I implore all of you to thoroughly read this guide before attempting to lap your CPU IHS.

We at the DGC DO NOT TAKE ANY RESPONSIBILITY FOR YOUR ACTIONS REGARDING LAPPING THE IHS OF THE CPU. This will most definitely VOID the WARRANTY of your CPU, and also there is a small chance that you can brick your perfectly good CPU if you do not take your time and use all precautions prior to lapping your CPU.

Basically you are on your own, if you wish to continue please read the guide thoroughly and TAKE YOUR TIME. This is a fairly simple task and can be done fairly quickly, and easily. You can perform this tweak on any CPU that uses a IHS, just make sure it does not have a small hole in the IHS (applies to older Intel 478 socket CPUs).

Items That Are Needed

Starting off with the sand paper that will be needed for us to lap the CPU IHS. From the bottom of the pile to the top of the pile and in order: is a 12×12 inch mirror (A glass pane of the same size or similar size will work just as good), wet/dry 800 grit sand paper, wet/dry 1000 grit sand paper, wet/dry 1500 grit sand paper, wet/dry 2000 grit sand paper (optional), and finally wet/dry 2500 grit sand paper (optional).

The supporting items that will be needed for us to lap the IHS of the CPU, these items are just important as the sand paper: a soft rag (A micro fiber cloth works perfectly), an eraser (Soft pink eraser that we used in grade school works best, like the one shown here), a soft bristled tooth brush (make sure it is a soft bristled tooth brush, if you use a medium/hard brush it will damage the CPU), rubbing alcohol (use the highest percentage of alcohol possible one shown here is 91%), and finally a CPU, not shown is a can of compressed air make sure you have one before lapping the CPU.

Lets Get Started

The CPU pictured here is none other then my Intel Core i7 2600K Sandy Bridge. I muffed up the coating that Intel used on the IHS so I felt it would make a perfect candidate for a lapping. Make sure the CPU is thoroughly cleaned, all traces of thermal paste has been removed use the rubbing alcohol to clean the CPU IHS up.

You will not have to do this step I marked the top with magic marker for me to see how flat the IHS is during my lapping.

Grab the 800 grit wet/dry sand paper, then carefully put the CPU on the sand paper (DO NOT USE WATER) IHS facing down. Like how I have it in the above image, now grip the CPU with three fingers, with the weight of your hand ONLY start sanding the IHS using 2-3 inch circles. Go clockwise then counter clockwise, you do not need to count the repetitions. This is the roughing stage so take your time.

I stopped and looked at the IHS periodically to check my progress. This is the first time I seen the IHS be this flat from Intel. As  you can see that I am removing the coating that Intel used on the CPU. Keep sanding till you see nothing but copper.

Now that is better, notice that I removed all of the coating that Intel used on the CPU IHS. Now again, this is just the rough stage I will polish up the IHS in a few.

Grab the 1000 grit wet/dry sand paper next. Using the same exact technique of holding that I used with the 800 grit sand paper (refer to the picture), use small 2-3 inch circles clockwise and counter clockwise. Just use the weight of your hand during sanding. Again DO NOT USE ANY WATER just sand dry.

Getting a little bit better on the IHS of the CPU. But, this is not good enough for me. time to move on to the 1500 grit wet/dry sand paper.

The 1500-2500 grit wet/dry sand paper is the final stage and polishing. Just use the weight of two fingers only (refer to the picture), I am using the 1500 grit sand paper for the first stage of polishing. Use the same small 2-3 inch circles for this step as well. Notice I am not using water, DO NOT USE WATER while lapping the CPU.

Looking at the finished result of my lapping the CPU with the 1500 grit wet/dry sand paper. Even I have to say this looks really good and polished to me. If you do not wish to continue on further please skip to the cleaning portion of this guide. I am going to continue on using a 2000-2500 grit wet/dry sand paper.

The 2000 – 2500 grit wet/dry sanding portion will be done exactly like what I did with the 1500 grit wet/dry sanding. Just make sure you DO NOT USE WATER during your sanding.

The end result of using the 2000 grit wet/dry sand paper.

Moving on to the 2500 grit wet/dry sand paper.

Final result of me sanding the IHS of the 2600K CPU. Now I am happy.

Up next is the cleaning process.

The Cleaning

When performing this step TAKE YOUR TIME. I am going to be messing on the same side as the micro pads that Intel used on the CPU that make contact to the CPU socket of the motherboard. If you rush this step you can and might dislodge one of the many little transistors on this side of the CPU rendering useless.

Grab your soft micro fiber cloth and lay it over the mirror. Then place your CPU IHS down on the micro fiber cloth.

Locate the soft bristled tooth brush and gently sweep the backside of the CPU off. Making sure you get in between the transistors in the center of the CPU. Use a can of compressed air to blow away any debris as you sweep the backside of the CPU.

You do not have to do this step if you feel uncomfortable, if you do please skip to the next step. But, I recommend this step as this cleans the pads up of any oils or debris that might have been placed on here during our sanding. Gently while performing this task clean the pads of the CPU up by running the eraser across the surface of the CPU. STAY ON THE PADS OF THE CPU, if you happen to have an AMD CPU DO NOT DO THIS STEP.

Now grab a corner of your micro fiber cloth put some rubbing alcohol on it then gently clean the back side of the CPU up.

Place the CPU IHS side up then clean that side too.

Ending Thoughts

Lapping the IHS is not as painful as one would think. It can only take a matter of minutes, from start to finish, to get a serious polish out of the IHS and therefore help reduce your overall temperatures of your CPU.  I did not post my results of the temperature difference from stock to lapped mainly because this will greatly vary on each and every CPU as they are not all the same. Typically the temperatures will drop anywhere from 4-8°C depending on the shape of the IHS is in, and the type of cooling that is being used.