STEP 6 : Install Heat Sink/Fan

Today’s processors are running quite hot. Advancements are being made to make them run cooler at higher speeds, but the importance of a high quality heat sink and fan cannot be overstated. PCs that are not properly cooled can be quite unstable, or at its worse, it may not even boot properly.

It used to be that you could attach a heat sink and fan to your processor directly and not worry about it. Today, though, processors run too hot to do this and expect a reliable PC. One must use heat sink compound to seal the gap between the heat sink and the top of the processor.

Some heat sinks have a rubber heat pad on the bottom of them. In these cases, you don’t really need to use heat sink compound because the rubber pad will create the seal. It should be kept in mind, though, that if you are using a heat sink which has been used before and had a heat pad, that heat pad is now likely melted in the spot where the previous processor contacted it. In these cases, you cannot use the heat pad again as it will be ineffective. Instead, you need to clean the old rubber pad off of the heat sink using a non-abrasive cleaning compound. Many people use isopropyl alcohol and a broken old credit card to scrape the rubber off without damaging the heat sink. When the pad is removed, you can use the heat sink again using heat sink compound.

  1. Attach the fan to the heat sink. This step is almost always already done for you, but if not, you must do it yourself. This is done using the four screws that came with the CPU fan.
  2. Clean the top of the processor. Using a lint-free cloth and isopropyl alcohol (or some other non-abrasive cleaning solution), ensure that the surface of the processor is clean and free of dust and finger oil. Do the same to the bottom of the heat sink. Pay attention to the note above on heat pads if your heat sink had or has a rubber heat pad.
  3. If you are using a cooling shim, place it onto the top of the processor now. Not all processors require shims. In fact, no processors require shims; they are completely optional. But, some people like to use them because they help to increase the surface area of the top of the ship and spread the weight around evenly. See, some processors (such as the Athlon XP) actually have the core sticking up slightly from the rest of the processor. So, when the heat sink is placed on top, all of its weight comes down on the core. If the fan is a real tight fit for the motherboard, it could really create a weight load on the processor core, and some people have actually crushed their CPU core by accident. A shim is simply a thin piece of metal, especially designed for a particular processor, which fits over the processor and evens out the height and helps to alleviate the crushed core problem. When installing a shim, be extra sure you are aligning it correctly. They often have holes in them exactly placed so that the cache bridges on top of the processor can poke through. If the shim is not properly aligned, you could short out these bridges and actually burn out your processor if you run your PC that way. Additionally, a mis-aligned shim could cause the heat sink to not actually have full content with the CPU core, leading to overheating.
  4. Apply the Heat Sink Compound. Assuming you are not using a heat pad on your heat sink, apply a very thin layer of heat sink compound to the top of the processor core. If, as is the case with Pentium IV processors, the top of the processor is totally flat, then apply the compound to the entire top surface of the processor. Many heat sinks come with heat sink compound in a small little package, usually just enough for a one-time install. You can pick up better quality compound online. Arctic Silver is a very popular choice. Be careful not to get compound on any motherboard electronics. Apply only a very small portion to the processor. Only a very thin layer is required. The compound must be spread out evenly across the top of the chip, forming that very thin layer. When spreading the heat sink compound, do not use your finger. Use the edge of a credit card, or you can use a rubber glove or even just a plastic bag over your hand. Do not apply any heat sink compound if you plan to use a heat pad.
  5. Attach The Heat Sink. Place the heat sink/fan combo squarely on top of the processor, pressing down lightly. Do not do any twisting as you install the heat sink. Press down firmly, but straight down so as to preserve the heat sink compound layer you just applied.
  6. Secure the heat sink. Most newer heat sinks use a set of clips on each side to fasten itself down. These clips attach to a pair of tabs on each side of the socket. It will probably take a little bit of force to bend the clip down over the tab. Other heat sinks wrap around the processor, then just sit on top, the compound being the only real attachment. Pentium IV motherboards have a heat sink retention bracket around the processor socket. When you install the P4 heat sink, you will fasten each of the four retention clips into the retention bracket and then close the clip levers on top of the heat sink to fasten the heat sink down onto the Pentium IV processor.
  7. Double-Check. No compound should have oozed out from the sides. If it did then you applied too much and need to remove the HSF, clean both the heatsink and CPU and start over.
  8. Attach fan to power source. Unless your CPU fan is powered via a standard power supply plug, it is probably powered by a wire attached to a 3-pin power lead on the motherboard itself. You can attach this now. The CPU_FAN power lead is located near the CPU interface somewhere. The lead will have two small pins on each side, and these pins surround the power plug and the pins are inserted into the holes in the plug. It should be pretty easy and obvious.

17 responses to STEP 6 : Install Heat Sink/Fan

  1. S0mEgUy June 11th, 2008 at 2:30 pm

    So if you have a heatsink already attached to the CPU (like in the previous step) you do not need to worry about this one?


  2. FireBert85 June 17th, 2008 at 4:38 pm

    Yeah sounds like it. Is the article also saying that some CPUs today come ready to be used without the heatsink/fan?


  3. pgde June 20th, 2008 at 9:21 am

    No, do not ever use a CPU chip without a heatsink or fan……Unless you want to go into thermal overload every time. As the above article says:

    “the importance of a high quality heat sink and fan cannot be overstated. PCs that are not properly cooled can be quite unstable, or at its worse, it may not even boot properly.’


  4. Paul August 13th, 2008 at 9:17 am

    Overclocking a chip is a really good reason to use one also. Many high-performance boards have a Bios written with overclocking your CPU in mind. A good comparison is a power sander in a carpentry shop. If you run it at normal speed, it will remove material at a rate that keeps the sanding disc cool, will shape your piece adequately, and will preserve the life of the disc. If you want to remove more material more quickly, you must find a way to keep the disc cool, or it will burn the wood. Same thing with an overclocked chip. Your sander is really chewing off the wood, faster than the design intended, and the only way to save the tools and materials is to lower the operating temperature. This can’t be done with a power sander, but it can with a CPU. I am not a fan of overclocking (forgive the terrible pun), as it is possible to buy faster processors, and it can violate the terms of warranty to overclock, and the life of the CPU is determineably greater when it is run as intended.


  5. Bob August 19th, 2008 at 11:49 am

    I have bought a AMD chip. I am a bit confused, my block came with fan atached. Do I use the heat sink to attach block to Chip? It seemed to me like it had a bit on there already. and if not, Y did my chip not come with heat sink to install?


  6. Spencer H August 31st, 2008 at 2:03 pm

    This website is awesome. I’m just about to build my first PC with the help of a more experienced friend, and he says that all this info is golden. Thanks so much for making this easy to find! :)


  7. Esun December 7th, 2008 at 6:12 pm

    This guide is not very thorough or complete (or totally correct).

    The heat pad is NOT rubber. In most cases it’s something wax based that allows it to melt and fill in the cracks between the cpu and the cpu heatsink/fan.

    The method for applying thermal paste is also not entirely correct–there are multiple ways to do it, but it’s preferable that you first grind both the cpu and cooler’s contact faces until they are smooth, DO NOT touch it, and then apply two lines of thermal paste onto the CPU, and then squarely push the cooler down on top of it to distribute the thermal paste. There are multiple ways to do this depending on the shape of the cpu and the surface of the cooler–usually the manufacturer of the thermal paste or cooler will provide instructions. Apply only a thin layer so it doesn’t ooze out.


    • Trollmaker August 1st, 2009 at 12:48 pm

      I agree that some parts of this article are incorect. It suggests that you should completely cover the CPU in thermal paste but i have read multiple instruction manuals that say this is an outdated method that does not work as well as applying the thermal paste in a line over the proccessing core. Most companies make guides for this. Artic silver has a picture oriented guide for single dual and quad core processors. My suggestion, follow the guide.


  8. JM January 31st, 2009 at 6:25 pm

    “first grind both the cpu and cooler’s contact faces until they are smooth…” Grinding? Totally unnecessary and risks damage.

    These instructions are spot on – I’d just mention the rule I use for Intel chips is to apply about “a grain of rice” worth of compound, and spread it very thin.


    • Ian June 11th, 2009 at 12:08 pm

      The spreading method may work but i just followed the Arctic Silver 5 instructions verbatim. Small thin line from left to right and leave unspread. CPU temp of i7-920 idles under 45 degrees C. To each their own i guess


  9. Flo February 16th, 2009 at 4:26 am

    The Website is really good and helps a lot not to forget something, but I must say that if I imagine 80% of my friends go ahead with building their own PC with this manual, they would really appreciate some basic pictures. I know different casings, processors, bla bla bla looks all drifferent, but it gives you a better idea as human learn and understand better with visual impressions. Maybe you could add some basic once for each step?


  10. Vinay March 11th, 2009 at 5:49 pm

    Does a dust-ridden heatsink malfunction? If yes, please provide me guidelines to clean it.


    • george June 23rd, 2009 at 3:22 pm

      just clean it with a soft brush because the dust can block the air from flowing correctly


  11. thehaf April 1st, 2009 at 8:28 pm

    My motherboard has a 4-pin cpu fan connector but my fan/heatsink came with a 3-pin female connector. It fits but one pin is not in use. Why i this?


  12. jonass21 April 28th, 2009 at 12:40 am

    I just installed a new xigmatek 92mm rifle heatsink to my athlon 64×2 kuma processor, but the heatsink didn’t completely cover the processor… is that a problem? it is only about 1mm that didn’t get covered


    • 101110100 September 18th, 2009 at 12:11 am

      as long as it covers the cores its fine


  13. Vijay December 4th, 2009 at 7:12 am

    hey i cant connect the processor fan properly,
    it shows on its ends as twist the sides.


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