Why Thermal Paste Is Essential For CPU Cooling System

Building a PC is a many-step process, but one in particular stands out as being intimidating to first-timers: properly mounting a CPU and cooler. Heat management is important to consider when constructing or maintaining your computer. Application of thermal paste is essential to keep the processor cool and happy. With processors working at increasingly higher clock speeds, concern with thermal dissipation is necessary because the higher the clock used, the higher the heat produced. A good contact between CPU and heatsink is crucial yet it is something more people get wrong than anything else.

What’s a thermal paste in the first place?

Why? Too much heat can spell death for your sensitive components, and if you’re overclocking it’s even more of an issue. Follow this general guide to reapply thermal paste after removing a heat sink or CPU during a repair. When using a thermal compound for CPU cooling you’ll always need to bear in mind a few important instructions for best results. To give you an idea, a 486DX2-66 dissipated somewhere between three and six watts, while a Pentium 4 processor with 3.8 GHz dissipates 115 W! Read on for a crash-course from the Labs.

thermal paste located between cpu and heat sink surface

Because, generally speaking, that one little cpu chip is simultaneously the smallest, most delicate, and most expensive part of your system. Knowing how to apply thermal paste correctly is one of the foundations of proper computer cooling. For more advanced directions, specific to your CPU, check out Arctic Silver’s page of application methods. If you don’t utilize a thermal solution compatible with the specific model of processor that you use in your system, several problems can appear: random resets, freezes, reduction of processor lifespan, and even burning the CPU in extreme cases. One of the most important factors when building a PC is managing heat output.

Thermal Compound or Thermal Paste?

Mount the cooler wrong, or improperly apply the thermal paste and you’re looking at (at best) a drop in performance and system crashes, or (at worst) a $200 disaster. Follow this guide to learn how. Thermal paste is responsible for conducting heat from the processor to the heat sink. Several solutions were proposed to solve those problems, including the elaboration of a new motherboard standard (the BTX standard was created to maximize air circulation inside the PC) and the launching of cases with ventilation ducts and liquid cooling systems. A modern CPU packs huge numbers of transistors into increasingly tiny pieces of silicon and when power is applied this has the potential to generate massive amounts of heat that need to go somewhere.

Types of thermal paste

But don’t worry! Choose the proper thermal paste. Reassembling a computer without applying thermal paste will cause the processor to overheat, resulting in permanent damage. Those solutions are still expensive, and we are not always willing to pay for them. This is where heatsinks come in.

make sure your motherboard will handle thermal paste correctly

It’s actually not terribly hard to install a new CPU, as long as you know what you’re doing. Most of the basic thermal grease compounds contain silicone and zinc oxide, while more expensive compounds contain excellent heat conductors such as silver or ceramic. Before applying a new layer of thermal paste, you must first remove any old thermal paste from both the processor surface and the heat sink. Individuals who work assembling and selling computers are aware of market problems and know how difficult it is to convince a client that the final cost of the computer increased due to a better cooling system. They are designed to take the heat generated in that tiny piece of silicon and take it away, keeping the processor from overheating and the silicon itself from being damaged.

Lowering the temperature of CPU surface

And so that you do know what you’re doing, we’ve put together a quick primer on installing a new CPU. The advantage to the silver or ceramic thermal grease is that you will have a more efficient heat transmission. Use the flat end of a spudger to scrape off as much solidified thermal paste from the copper core(s) of the heat sink as possible. Not every heat sink thermal paste is deemed good. In fact there are cheap worthless thermal pastes in the market that are not even worth looking at. Usually, the client is not very interested in that; their only concern is the price. This heat transfer is important, and most of the time PC and laptop overheating can be traced back to poor heatsink efficiency.

Wrong thermal paste application

Metal thermal compounds usage in modern systems

If you’re a newbie getting ready to build a new system, or an old pro looking to make sure your technique is the best, read on to find out everything you need to know about properly mounting a CPU. However, the basic thermal grease will sufficiently fit the needs of most people. After scraping off the solidified thermal paste, a residue is still present on the copper core(s). Use a coffee filter or a lint-free cloth with a drop of ArctiClean Thermal Material Remover to clean the thermal paste residue off the thermal contact surface of your heat sink. A simple and inexpensive solution is the utilization of thermal paste (also known as thermal grease or thermal compound) that can help reduce the problem of processor overheating. One of the major causes of this is the interface between the heatsink and the processor.

Thermal paste is a type of heat transferring agent that serves to fill in the microscopic gaps that naturally occur when two flat metal surfaces—such as your CPU and cooler—are pressed against one another. If you are planning on overclocking your computer, try to get thermal paste comprised mainly of silver, copper, and gold. Once the surface is clean, use a new coffee filter or cloth to apply a drop of ArctiClean Thermal Surface Purifier to remove any oils and prepare the surface. The paste must be used with the right cooler for the specific model of processor installed. Most modern processor packaging includes a heatspreader.

Always use a top-notch brand of thermal paste

Advantages of high-end thermal pastes

These air-filled gaps hinder the rate at which the cooler is able to absorb heat from the CPU, and filling them with thermal material greatly increases performance. These are the most conducive metals that thermal paste can be made of. Do not touch either the chip or the heatsink, or allow any dust or debris to get on them. In this tutorial, we’ll discuss the role of thermal paste in the process of thermal dissipation, how to correctly use it, and the most common mistakes made during thermal paste application. This is a metal cap that sits over the silicon itself and helps to move the generated heat to a larger area.

There are several different types of thermal material, including ceramic- and metal-based pastes and solid, waxy thermal pads. Clean the CPU and heat sink surfaces. Even a fingerprint can be a major obstacle to thermal transfer on a chip. We have a follow-up review to this tutorial, called “What is the Best Way to Apply Thermal Grease” that you should read as well. Heatspreaders first appeared on Intel’s Pentium 4 (and a couple of later generation Pentium3 CPUs) and were introduced by AMD with the Athlon 64.
Some coolers come with pre-applied pads, but most don’t, and we recommend using a paste. Wipe the surface lightly with a cotton ball or cotton swab dampened with isopropyl alcohol. With using a top-notch thermal paste with high performance you make sure your CPU is as cool as possible to perform at its peak level without any hassle. Allow the heat sink(s) to dry completely! The device used to remove the processor’s heat is the cooler. Previous to this, heatsinks needed to be mounted directly onto the silicon die of the processor.

The low price is not an issue at all

Our two favorites are Arctic Silver 5 and Arctic Silver Ceramique. The higher the percentage of alcohol the better. 70 percent is good but 90 percent is better if it can be found. Use the flat end of a plastic spudger to remove any solidified thermal paste from the surface of the processor(s). Do not use any metal objects for this procedure. Each processor requires a specific type of cooler. However, as die size continued to shrink so did the silicon size, which caused two problems.

  • we will test each technique in a full computer system to see which has the best thermal performance.
  • noble materials that promise more efficiency in heat transmission.

  • Thermal paste can be found in many kinds of packages and usually comes with the cooler.
  • If you break the seal that is created when you install the heat sink
  • Truth is, all you’re trying to do when applying thermal paste is to get a paper-thin layer of the stuff over as much of your CPU as possible.

If you’re using a CPU, cooler, or both that’s already seen a tour of duty, then they’re likely to have some gunky thermal paste residue. Sand the heat sink and processor surfaces if necessary. Be careful not to break any components on the processor’s surface, or get any thermal compound loose on any components (conductive pastes could cause problems) Again, use a coffee filter or lint-free cloth and a drop of ArctiClean Thermal Material Remover to clean any thermal paste residue off the processor surface. The use of an inefficient or wrongly dimensioned cooler can cause overheating problems. The first was that destroying a CPU while trying to mount a heatsink became easier and easier (smaller dies like ‘Barton’ core Athlons were notorious for this) and the second was that it became incredibly thermally inefficient to try to transfer heat from such a small area.

High connectivity

Don’t be tempted to just reuse this old paste, as it dries out over time, and you won’t get a clean connection between your CPU and cooler. Ideally, the two touching surfaces will be perfectly flat, which would completely eliminate the need for thermal paste. Use a new coffee filter or cloth to apply a drop of ArctiClean Thermal Surface Purifier to remove any oils and prepare the surface. However, the cooler alone doesn’t solve the overheating problem. An integrated heatspreader allows the contact area between the processor and the base of a heatsink to be larger, which increases the potential amount of heat transfer.

Heat transfer between heatsink and CPU
So the first order of business is to clean off the old thermal material. If your heat sink base is rough, you can wet-sand it down and polish it to make it smoother. Allow the processor(s) to dry completely! There’s another “bad guy” in the story: heat transfer between the processor and the cooler. It also completely removes the ability to destroy a silicon die while installing a heatsink, making life easier for all.

Heat dissipation rate

Here in the lab we use a two-stage cleanser called ArctiClean, although high-percentage rubbing alcohol will do the job just fine. This isn’t always necessary, unless you are aiming for the ultimate cooling performance. Wrap the tip of your index finger with a piece of plastic (such as a sandwich bag or Saran wrap). Dispense a very small amount of thermal paste onto processor core(s). Use your finger to gently smear the thermal paste over the entire processor core(s). Using a CPU thermal paste has been proven to be essential for every computer built. If you accidentally apply a small amount of thermal paste on the green surface of the processor, it will not cause any harm. From the microscopical point of view, the physical contact between the processor and the cooler isn’t perfect. You want to ensure that your heatsink and CPU have as close a contact as possible.

Just apply a drop or two to the old material and let it sit for a minute while the cleaner breaks up the grease in the thermal paste. Thermal paste is designed to fill in the gaps and imperfections on the surfaces that you are joining. The processor(s) is now ready for heat sink installation. Imperfections that exist both on the processor surface and the cooler surface prevent their being a 100% perfect contact between them. Heatsink brackets are designed to put downwards pressure on the heatsink in order to achieve this, but the mating still isn’t perfect.

Then, wipe it clean with a lint-free cloth. Since modern production techniques cannot make surfaces without imperfections, thermal paste will always be necessary. You do not need to apply any thermal paste on the heat sink(s), although Arctic Silver gives instructions on “tinting” the heat sink to reduce the break-in time of the thermal compound. As both surfaces aren’t perfectly even, minuscule gaps of air are formed when putting them together. The reason for this is that, while the base of a heatsink and the top of a heatspreader look to be incredibly smooth to the naked eye, this doesn’t translate at a microscopic level.

lots of heat will devastate the CPU

Importance of monitoring the generated heat

A coffee filter makes a terrific, cheap lint-free cloth. Because air is a terrible heat conductor (its conductibility coefficient is 0.026 W/m°K), the heat will pass with more difficulty from the processor to the cooler, which can result in overheating. Now you may ask then, what’s the best thermal paste out there? you may want to read more about this here. Microscopic surface imperfections lead to air gaps between the two surfaces. Repeat the process until both the CPU and cooler are totally clean, and then move on. To solve the problem and improve the heat transfer between the processor and the cooler, we should apply thermal paste between them in order to fill in the tiny gaps of air.

Air is a horrible conductor, so these gaps decrease the heat transfer to the heatsink. By doing so, the heat transfer between the processor and the cooler is easier since the thermal paste has a higher conductibility coefficient than the air. The way to minimize this impact is to use a Thermal Interface Material (TIM).There are various kinds of TIM out there, but the most relevant for PC builders is thermal paste. Thermal paste can be found in electronics parts stores. This is a goo made out of some kind of conductive material suspended in grease.

Different brands in the markets

Its use is indispensable and it’s a very inexpensive component. The theory is that when you apply this between the heatspreader and heatsink you fill in those microscopic gaps with a material that is more suitable than air for conduction. On the following pages, we will discuss how to correctly apply thermal paste, as well as stating the most common mistakes made when applying it. This is important because metal to metal heat transfer is the ideal situation. While you want to eliminate air gaps your thermal paste isn’t supposed to get in the way of this direct metal heat transfer.

try not to overuse the thermal paste

There are several ways to do this – serious overclockers use a technique called Lapping, where both the heat spreader and base of a heatsink are smoothed out with fine sandpaper, the theory being that the eventual mirror finish that emerges give a much better contact between the two. Lapping is overkill for 99% of the PC-owning population though, and the best way to maximise thermal transfer is to apply thermal paste in the correct way – sparingly. If you are installing a retail packaged processor and heatsink the tough work is already done. Retail Intel processors come with a small amount of preapplied TIM on the stock heatsink. It is a relatively small amount in three stripes.

  1. The best technique to apply thermal paste is something that is often debated on the internet.
  2. The thermal paste is basically composed of silicone and zinc oxide.
  3. Its price can range between USD 2 and USD 32 (in pastes that have silver in their composition).
  4. Avoid removing the heat sink after installing it. It can be difficult to check if your paste has been applied correctly.
  5. Reconnect the fan to the motherboard. The CPU fan wire should be plugged in the CPU fan socket
  6. Looking around the internet, you’ll find a lot of different philosophies about how to apply thermal paste.
  7. First we will see how each technique spreads the thermal paste across the CPU.

This gives the TIM room to spread out under heat and pressure, making for a good mating. If you don’t have pre-applied TIM you’ll need to apply thermal paste yourself. Remember that you want to fill microscopic air gaps, which means a small amount of paste. Thermal paste is an efficient conductor, but nowhere near as efficient as bare metal. So if you use too much paste you can end up in a situation where it sits in a thick layer between the heatsink and CPU and reduces the ability to transfer heat.

Last Words

The other potential side effect with too much paste is that it oozes out the side of the heatspreader and into the socket. This can range from inconveniently messy to potentially disastrous(some thermal pastes will use metals like Silver, which are electrically conductive as well). What you want to do is use as small an amount as possible. Some more advanced metallic thermal pastes can be applied in a few drops in the centre of the CPU, and the pressure will spread it. But ideally you want to apply a small smear across the top of the processor. Our preferred means of application in the PC & Tech Authority Labs is a plastic-coated business card, but some thermal pastes will also come with applicators.

What you want to do is ensure a relatively thin smear across the surface of the heatspreader – toss out any excess that protrudes over the sides. As long as the coverage is thin then don’t worry too much if it looks a bit uneven – the pressure from the heatsink will help with that.

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