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The CPU Fan
The CPU fan's role is exclusively to cool down your processor,. There are two components to the fan assembly:
- the heatsink
- one or more fans
It is an essential component for any computer because no computer processor can function properly without it. The CPU fan is entirely dependent on the type of socket you choose for your CPU and it's needs for heat dissipation.
The CPU fan usually adjusts its speed to the temperature through a wire connected to the CPU's own sensor. It is also important to make sure that the computer case has a size that allows a bigger custom fan to fit inside of it.
Some processors come with a stock fan by default and others don’t. Make sure to double-check the details on the CPU you purchase beforehand. Processors require a fan and heatsink to work at all times. A stock fan will not allow you to overclock the processor, but it can still be a good option in some cases. For example, some stock-fans come pre-installed on the CPU so you don't have to.
- If you are absolutely sure that you will never even try to overclock your processor
- If you are not familiar enough with computers to tweak BIOS settings for overclocking
- If you are not familiar with installing computer hardware components
In those situations, you can stick with a stock CPU fan, but makes sure to clean the dust out of it often.
Why do you need a Custom Fan
Why are do you need a custom fan, if processors come with a default one, you ask? It's because the stock fans are not very good for the heavy demands that 3D renders impose on it. Your processor will be heavily solicited at almost maximum capacity and for long periods of times.
For example, with normal computer operations like email, internet and excel charts, the processor is used at 20%. Sometimes, you may see occasionnal spikes at 75% with more visual applications, such as netflix, but it's still not continuous. However, when doing 3D renderings, your processor will be heavily sollicited at 100% capacity, almost at all times, except during the write to disk process.
This is why we recommend that you immediately upgrade to a custom CPU fan if you'll be doing 3D renders. A failure of the fan, will result in the CPU being burned to a non-functionning state, or if you're lucky, a complete shutdown. Therefore, you will need a reliable source of cooling and a steady power supply. If you plan on overclocking your CPU, this is a no-brainer, you must absolutely get a quality custom fan, or better.
Extreme cooling options, like liquid coolant, are also an option for extreme overclocking, but not necessarily required to overclock your CPU moderately (which is what we want for optimal system stability), but good CPU and chassis fans as well as a computer case with good airflow are required to do so. Liquid cooling adds considerable complications and risks to your setup, especially if you are just starting up, but the cooling effect is maximized.
Note that liquid cooling is not fanless. There are still fans to cool of a heatsink, but the heat is transferred through a gel instead of a metal pipe, which is more efficient.
The Overclocking Question
Selecting your CPU fans depends on the wattage of the CPU and the amount of overclocking you plan to try. A stock fan will not be sufficient for overclocking, but you can invest in specialty fans to allow you to boost the speed of your CPU considerably. You can get anywhere from 10% to 40% if you have good cooling, at little more cost. There are however and a few risks, so make sure you thoroughly read forums about overclocking before you begin.
What to Look For?
The CPU fan is not the only thing to contributes to a good heat management. The heatsink materials and design, as well as the fan configurations in the case are also important to consider. Make sure you also select a good computer case and chassis fans.
Aiflow is measured in Cubic Feets per Minute (CFM). A good fan should be able to produce over 65CFM and ideall over 80 CFM. There are many factors that contribute to a good airflow in a computer fan:
- Number of Fans
- Blade Size
The first difference you will notice when upgrading from a stock fan to a CPU fan is that the air is no longer 'pushed' into the heatsink flat onto the CPU, but it rather 'passes through' a perpendicular heatsink, connected with bronze heatpipes to the CPU. This is a much more efficient design in terms of heat dissipation, but it also means a more stable efficiency. Indeed, the dust isnt' being accumulated as much onto the heatsink, reducing it's power to dissipate heat over time.
Oftentimes, custom CPU fan assemblies have more than one fan in a 'push' and 'pull' configuration. We recommend an assembly with 2 fans for optimal performances. The first one pushes air in from the front, and the other pushes it out of the heatsink, sending the hot air through the back of the computer case.
Blade Size and Number
The main factor that contributes to good airflow in a computer is the the size and number of fan blades. You will enjoy the added benefits provided by a larger fan in multiple ways. The size of the fan will mean a better airflow with a lower RPM, and a lower noise. Since there are only benefit, try to find the fans with the largest blades as possible.
The second factor to consider is the number of Revolutions-Per-Minute (RPM). And contrary to popular belief, it is not the most important factor to consider when it comes to a good airflow. RPM certainly does contribute to airflow, but is not as interesting as the number of fans or the blade size. That's because a higher the RPM means a higher level of noise. In this case, higher is not always better.
Heatsink Materials & Design
A heatsink is a series of metal sheets aligned to form the largest possible surface area to dissipate heat. They are affixed to the motherboard and case, but they hold right onto the surface of the CPU, touching with a thermal conducting paste. Try to find a silver thermal paste instead of a ceramic one, that will stay conductive even when it dries up with time and heat.
Better quality heatsinks usually come with copper heatpipes instead of aluminium ones. Look for a fan with as much heat pipes as your budget will allow (4-8). This makes it more conductive to heat and more effective at heat dissipation.
The problem in 3D rendering comes when the CPU fan cannot cope with the amount of heat produces. This will force you to halt renderings periodically or to reduce the performance of the CPU you have.
Noise Level (db)
An important and often overlooked aspect of fans is the noise production. There is nothing more annoying than a computer that makes a huge jet engine noise. Noise is also a sign of inefficiency, from the friction between components. It indicates a wear that will mean lower durability and reliability. Therefore you need to find a CPU with as low a decibel (db) rating as you possibly can, by using a popular brand.
For reference, here are the common noise level references. You can find out more about it here.
- 35 db: Quiet Room
- 40 db: Noticeably distracting sound
- 45 db: Radio in the Background
The noise is not always perceptible when you start your computer, but it will become much more annoying when the temperature rises during 3D renders. This will push the variable RPM to the maximum range and test the limits of endurance of your ears.
Choose a known brand that aims to maximize airflow, minimize noise and guarantee reliability. Here are our recommendations:
- Arctic Freezer
You can expect to spend between 25$ to 100$ for a quality custom CPU Fan, that has good airflow and low noise.
only 36 db, perpendicular flow
For smaller cases: 120 mm x 70 mm
2 Fans, 2 Heat Pipes, 140 mm
Extra: Liquid Cooling
240mm radiator+2x120 fan, RGB
Pro: High-End Air Cooling
2x120 mm fan, 8 heat pipes, LED
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