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 Post subject: Optimal price range for CPU Coolers.
PostPosted: Mon Apr 23, 2018 10:42 pm 
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Joined: Sat Sep 23, 2017 6:49 am
Posts: 124
In CPU temperature benchmarks from reviewers, I've seen minimal differences between higher end air $70-90 low-noise coolers such as Noctua NH-D15 or Be Quiet Dark Rock Pro 3 compared to a mid-range low-noise cooler such as the Scythe Mugen 5 ($45). While it seems that all 3 of these quiet coolers are good in their own right, there's a diminished returns in CPU cooler once going above the $30-50 range. Stock coolers from both Intel and AMD are noisy, and upgrading to an aftermarket air cooler does make a significant difference. There are good options at all price ranges, but PC builders need not spend double in order to get silent cooling and improved performance.

If the CPU is not being overclocked, performance and temperatures aren't a big issue as Intel and Ryzen CPU's are energy efficient at their default clock speeds. In this case, silence is the only consideration and a budget-end low-noise cooler such as Be Quiet Pure Rock Slim won't offer any less performance than a high-end cooler.


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 Post subject: Re: Optimal price range for CPU Coolers.
PostPosted: Tue Apr 24, 2018 8:44 am 
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Location: Guatemala
Imo $50 is the sweet spot, where you get a very capable cooler with a good fan, like Scythe Mugen 5 RevB, ninja 5, Kotetsu mII, Thermalright Macho RevB and True Spirit 140 Power.

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Last edited by Abula on Fri Apr 27, 2018 5:50 am, edited 1 time in total.

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 Post subject: Re: Optimal price range for CPU Coolers.
PostPosted: Thu Apr 26, 2018 7:25 am 
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Joined: Wed Jul 22, 2015 3:17 am
Posts: 45
I agree, $50 is a good balance of performance and price.
But getting a good air cooler is only half of the job, the other have being setting up case airflow to supply CPU cooler (& GPU cooler) with cool air at or near room ambient. The reason is that for every degree warmer the air is going into coolers when system is working hard translates into about a degree hotter the component will be .. and most cases do not have good enough or enough fans to do that properly.

Simple explanation of how airflow works
Airflow is simply displacement; for air to come into case, air must be leaving case .. or .. for air to leave the case, air must be coming into case.

Think of the air around us as water and we are divers in it and a sunken van is a computer case.
  • We can't move more water into the van (case) through an open window (vent) unless we have another open window (vent) somewhere else in the van (case) moving the same amount of water (air) out through a window on other side of van (case).
  • We can't take any water out of van unless we have the same amount of water coming in at the same time.
  • This means we have to have as many open windows flowing water into van as we have open windows flowing water out.
  • This is exactly how airflow works. Intake fan pushing / flowing air into case is pushing / flowing the same amount of air out of case.
  • Adding an exhaust fan can help case airflow, same as adding a back fan on some coolers.
  • But with good case intake fans we don't need exhaust fans, same as good cooler / radiator fans don't need pull fans. Image
  • This is why I used to always change stock intake fans. Now some cases are finally coming with intake fans that have high enough pressure ratings to not need 'helper' (exhaust) fans. Image


Basic tutorial of how to setup a case for optimum cooling
Setting up the case for optimum cooling is often the hardest and most time consuming part of a build... And the most neglected by most builders.
  • There is much more to cooling than good cases and good CPU / GPU coolers. Add the fact that many GPU's make more heat than CPU means getting that heat out of the case and keeping a cool airflow to components can be a challenge.
  • Cases, especially those with filters, usually benefit from fans with higher static pressure ratings than stock fans... "cooler" fans instead of "case" fans.
    Intakes typically have more restricted than exhaust because of air filters, more restrictive grills, HDD cages, etc.
  • I prefer mostly just good pressure rated intake fans and rarely use exhaust fans anymore .. but instead used high enough pressure rated intakes with exhaust vents being the only other openings in case. This allows intake fans to push air though the case and out. And don't confuse number of fans with amount of airflow... or airflow with airblow
  • airflow is flowing cool air from intake to component and flowing hot air from component out of case without the hot air mixing with the cool air.
  • airblow is lots of fans blowing air with some of hot air from components mixing with cool air making it warmer resulting in warm air not cooling components as well as the cool air will.
  • Putting fans in case as intake and/or exhaust is only the first step. These fans only move air in and out of case.
  • This does not mean heated air is not mixing with cool air.
  • Nor does it mean cool air is going to where it is needed.
  • Getting the air to flow inside of case properly is even more important. We still need to manage where the air flows inside the case. We can do this several ways; deflectors, more intake fans.. & exhaust fans, removing vent grills, removing HDD cage, using fans with higher pressure/airflow, building ducts to or from CPU/GPU cooler, etc.
  • Using a remote temperature sensor to monitor what air temps are is the key to finding out where the cool air is flowing and knowing heated air is not mixing into it. By monitoring this we can than make changes to get airflow the way we want it.
  • Keep in mind your case needs to flow more air than components do. It isn't so much how many fans but how well they flow air through the case. If component fans move more air than case fans move through case components are using their own heated exhaust to make up the difference and case heats up. Good rule of thumb is 25-50% more case cfm than component cfm but well tuned airflow can be almost equal equal.
  • Traditional tower cooler exhausting toward back of case must have rear / rear & top back case exhaust fan that remove as much or more cfm than cooler fans exhaust.
  • A duct from back of cooler to back of case (like Thermalright HR-22 uses) is also an option that works very well.

Example of Cool & Quiet System
  • My years old Define R2 system has three TY-140 74cfm intake fans. (no exhaust fans) in case while CPU has TY-143 130cfm fan and GPU has two TY-100 44cfm fans
  • Case = 222cfm
  • Components = 218cfm
  • Air temp inside of case going into coolers is never more than 3c above room.
  • 2 front TY-140 1300rpm intake fans match airflow demands of CPU cooler TY-143 2500rpm fans, both PWM controlled by CPU fan header
  • Bottom TY-140 intake fan supplies airflow demands of & GPU TY-100 fans and are PWM controlled by GPU

It is amazing how much cooler a system runs (and quieter) once the case airflow is setup to keep heated exhaust from contaminating cool intake air. Once we start doing these things, the concept seems like a no-brainer, yet most users seem to think more fans and/or powerful fans are needed to get better cooling. The reality is it's not so much the power and amount of air the fans move. but the currents / pathways the air flows in on it's way through the case that is important. Fan power/airflow only needs to be a little more than the amount the components are using at any given time. Using too many, fan and having too much airflow airblow can be as detrimental to case's flow pattern as not using fans with enough flow .. and if the flow isn't tuned to keep cool and heated air separate the system is not going run as cool as it can.


How to monitor air temperature different places inside of case:
  • A cheap indoor/outdoor thermometer with a piece of insulated wire and a plastic clothspin works great.
  • Made up with floral wire and tape. We don't want anything to short out with metal. Image
    [url="http://www.overclock.net/content/type/61/id/1832154/"]Image[/url]
  • Clip and position sensor where I want to check the temp. Make it easy to see what the air temp going into components actually is relative to room temp. Image
  • Optimum cooling is when air temps going into coolers only being 2-3c warmer than room.. 5c or less is good.


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 Post subject: Re: Optimal price range for CPU Coolers.
PostPosted: Fri Apr 27, 2018 5:29 am 
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Joined: Tue Nov 04, 2008 6:03 am
Posts: 604
Location: Sweden
doyll wrote:
Airflow is simply displacement; for air to come into case, air must be leaving case ...
Think of the air around us as water...
No, this is wrong/bad.
Air is a compressable gas, water is not.

Airflow is something that nature creates sponatneous when there's a difference in air pressure between two places.
You create flow by generating a pressure gradient.
If you look at a weather chart you'll notice that the (low altitude) air moves outwards from high pressure and into low pressure.

Let's say you have an airtight case and suck most air out of it. If you then open a valve air will flow into the case without any air going out. That airflow will continue until the pressure inside the case is the same as outside.
Alternately, if starting at equilibrium you can have a fan blow air into the case. There will be a flow until the difference in pressure between inside and outside of case matches what the fan can generate.

doyll wrote:
[*]airflow is flowing cool air from intake to component...
[*]airblow is lots of fans blowing air with some of hot air from components...
These definitions are yours alone.

The generally accepted definitions are:
Airflow: Any motion of air between two points or through a defined volume.
Airblow: An airflow onto (and then past) something.


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 Post subject: Re: Optimal price range for CPU Coolers.
PostPosted: Fri Apr 27, 2018 7:40 am 
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Joined: Wed Jul 22, 2015 3:17 am
Posts: 45
Olle P wrote:
doyll wrote:
Airflow is simply displacement; for air to come into case, air must be leaving case ...
Think of the air around us as water...
No, this is wrong/bad.
Air is a compressable gas, water is not.

Airflow is something that nature creates sponatneous when there's a difference in air pressure between two places.
You create flow by generating a pressure gradient.
If you look at a weather chart you'll notice that the (low altitude) air moves outwards from high pressure and into low pressure.

Let's say you have an airtight case and suck most air out of it. If you then open a valve air will flow into the case without any air going out. That airflow will continue until the pressure inside the case is the same as outside.
Alternately, if starting at equilibrium you can have a fan blow air into the case. There will be a flow until the difference in pressure between inside and outside of case matches what the fan can generate.

doyll wrote:
[*]airflow is flowing cool air from intake to component...
[*]airblow is lots of fans blowing air with some of hot air from components...
These definitions are yours alone.

The generally accepted definitions are:
Airflow: Any motion of air between two points or through a defined volume.
Airblow: An airflow onto (and then past) something.

True, air is compressible and air is not, but the principles of flow are the same for air as for a liquid. It is all the science of fluid dynamics.

Wikipedia definition:
"Airflow, or air flow is the movement of air from one area to another. The primary cause of airflow is the existence of pressure gradients. Air behaves in a fluid manner, meaning particles naturally flow from areas of higher pressure to those where the pressure is lower. Atmospheric air pressure is directly related to altitude, temperature, and composition."

and:
"Types of airflow
Like any fluid, air may exhibit both laminar and turbulent flow patterns. Laminar flow occurs when air can flow smoothly, and exhibits a parabolic velocity profile; turbulent flow occurs when there is an irregularity (such as a disruption in the surface across which the fluid is flowing), which alters the direction of movement. Turbulent flow exhibits a flat velocity profile."


my airflow and airblow definitions are only to point out that simply adding fans to a case does not create the kind of airflow needed.

My guide to airflow is not directed at people with the scientific / meteorological knowledge. I tried to keep it short so readers do not get bogged down and leave instead of finishing it, learning a little and being able to apply that knowledge to improving their case airflow and component temps.

If you think you have a better way of explaining things please post what you think I should change and if I agree I will edit my guide giving you credit for your help.


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