Lapping is a process in which you sand down the ISH of the processor to get a better heat transfer.
*Important: Lapping your processor and/or heatsink will void the manufacturer’s warranty. Overclocking.ca does not take any liability if you destroy your CPU by lapping it too much. When it comes to lapping use common sense and don’t use any power sanders.
Lapping your processor and/or heatsink is a great, safe and free way of decreasing the operating temperature of your processor. By decreasing the operating temperature of the CPU this will potentially allow you to get a higher overclock. When you put your heatsink on the IHS of the heatsink there are little gaps that can allow air through and not make perfect contact with the CPU. By lapping you are making the surface as flat as possible to allow the best heat transfer from the CPU to the heatsink.
There are a couple of things that you should note before deciding on lapping your CPU or heatsink. The first thing is that if you have a “direct touch” heatsink you will not be able to lap this heatsink. A “direct touch” heatsink is a heatsink where the heatpipes come in direct contact with the IHS of the CPU.
You can still lap the CPU if you will be using a “direct touch” heatsink. The second thing is before lapping, do a razor test – put a razor’s edge across the CPU from multiple angles and hold it up to a light. If you see light under the razor, the IHS is not flat and you’d most likely benefit from a good lapping. If it’s flat to begin with, there will still be a benefit, but potentially not significant enough for the trouble (meaning 1-2C as opposed to 4-5C), unless of course you want every single degree you can get and would be satisfied with a relatively small decrease in temperature.
What you will need:
- CPU and/or Heatsink
- Sandpaper of the following grits: 220, 400, 600, 800, 1000. (1200, 1500, 2000, optional). You will want to get 2 or 3 sheets of each grit. These can be found at any auto body supply store.
- Flat surface such as a sheet of glass, plexiglass, piece of marble
- Tape, to hold down the sandpaper to the flat surface
- 90% Isopropyl alcohol
- A foam piece large enough to cover the back surface of the CPU. You can also use the black plastic cover that came with the CPU.
The process is very easy but it is time consuming and tedious. If you are the kind of person that gets bored easily this might not be for you.
The Steps:
- Clean all residue from the surface of your processor using cotton swabs and 90% Isopropyl alcohol.
- Tape down 220-grit sandpaper on your flat work surface. Glide your processor over the sandpaper using a slow, circular motion. Use even pressure on the processor and let the sandpaper do the work.
- Check your work every 5 minutes by examining the surface of the processor. You will probably find that the plating is not wearing off evenly; this is a sign that the processor would not have made even contact with the heat sink. Your goal is to expose all of the copper beneath the IHS; this will take approximately 10 to 15 minutes of sanding.
- Stop sanding when the nickel or aluminum plating has been removed and the copper surface has been exposed. Discard the 220-grit sandpaper and place the 400-grit sandpaper on your work surface. Continue sanding.
- Use increasing grits of sandpaper as you continue lapping. Each grit will require less sanding time than the one before it.
- You can stop sanding when the surface of your processor is smooth and shiny. You can continue with the higher grits of sand paper if you are a perfectionist and want that mirror image shine. This is not necessary as there is little benefit in doing this.
- Once you are done lapping your processor, clean it off with a cotton swab and 90% Isopropyl Alcohol and let air dry for a few hours before putting it into your computer.
In all, the lapping process could take 2 hours to complete.
When it comes to lapping your heatsink or your waterblock, use a back and forth motion instead of using the circular motion.
If you have any questions, please leave a comment.
- Jerry
Tags: CPU, Heatsink, Lapping, Processor, Waterblock