CPU water cooler which way should I point the fans?

Rachid Khamlichi · 31 Aug 2018 at 23:52

6122_99_corsair_hydro_series_h105_extreme_performance_liquid_cpu_cooler_review.jpg

Hi I just brought the above cooler, and not sure if I should have the fans;

A: blowing air out of the case.
OR
B: Blowing air into the case onto the CPU.

Can anyone help please. Thank you,

MissChief · 1 Sep 2018 at 00:09

Generally blowing through the radiator out of the case is preferable, but it doesn't have to be like that. My case has the twin Rad on the front blowing IN though the rad. You will get better performance with the fan blowing through the rad instead of sucking through though. What case do you have?

Rachid Khamlichi · 1 Sep 2018 at 00:13

MissChief said:
Generally blowing through the radiator out of the case is preferable, but it doesn't have to be like that. My case has the twin Rad on the front blowing IN though the rad. You will get better performance with the fan blowing through the rad instead of sucking through though. What case do you have?

What do you mean by blowing through the radiator out the case?

I have the thermaltake suppressor f51 case

MissChief · 1 Sep 2018 at 00:19

So the fans push air through the radiator and then out of the case, either through the top of the case or at the back if there's enough room.

ilc72 · 1 Sep 2018 at 00:38

Rachid Khamlichi said:
Hi I just brought the above cooler, and not sure if I should have the fans;

A: blowing air out of the case.
OR
B: Blowing air into the case onto the CPU.

Can anyone help please. Thank you,

Generally speaking you’d want the hot air blowing out of the case, whilst it’s OK the other way round you want to make sure you have at least as many other fans blowing air outside the case so other components such as the GPU aren’t breathing hot air. Generally as a guideline you want as many exhaust fans as intake fans to ensure there isn’t too much negative air pressure, since depending on the case having too much negative pressure can cause air and therefore contaminants such as dust to be sucked into the case through areas where there may not be a dust filter.

However, each case is unique and so there are no absolute rules so sometimes it can be a trial and error process, especially in smaller cases.

Rachid Khamlichi · 1 Sep 2018 at 00:42

Okay so I am doing exactly what you guys said but for some reason my idle CPU temp at a noisy 65% speed is in the mid 40's to high 30s

ilc72 · 1 Sep 2018 at 01:59

Which CPU are you using? Some AMD CPU’s report a higher temperature (delta 20 degrees), suggest you download HWInfo64 if that is the case and see what temperatures that is reporting.

Can you confirm the model of the cooler as I don’t recognise the CPU header?

Finally stupid question but did you remove any protective covering on the CPU block? Also which header on the Motherboard is the fan header plugged into? Always use CPU_FAN as this is what most motherboards regulate to control fan speeds on AIO coolers.

Rachid Khamlichi · 1 Sep 2018 at 02:33

ilc72 said:
Which CPU are you using? Some AMD CPU’s report a higher temperature (delta 20 degrees), suggest you download HWInfo64 if that is the case and see what temperatures that is reporting.

Can you confirm the model of the cooler as I don’t recognise the CPU header?

Finally stupid question but did you remove any protective covering on the CPU block? Also which header on the Motherboard is the fan header plugged into? Always use CPU_FAN as this is what most motherboards regulate to control fan speeds on AIO coolers.

My cpu is Intel Core i7-7800X 3.5GHz (Skylake X / Basin Falls)

Cooler model is https://www.amazon.co.uk/dp/B00HKEI3EY/ref=pe_3187911_189395841_TE_dp_2

Yes I removed the block haha

Yes I plugged it into the CPU_FAN and the pumps into the pump socket.

UPDATE: I reseated the cooler it was not touching the cpu fully I do not think, added some more cooler master thermal paste - and now I am getting idle temps ranging from 27 to 30.

ilc72 · 1 Sep 2018 at 02:44

The Skylake X chips do run hot I’m afraid and the cooler has the slightly noisier SP120 fans but glad you found the solution. Sometimes the thermal paste can get a bit dried out but suggest for longevity to get a cleaning cloth out and apply some Thermal Grizzly Kryonaut paste, also with Skylake X make sure you apply the thermal paste properly as it’s a big processor die. Have a look out for Gamers Nexus videos on YouTube as they give good instructions on the process.

Rachid Khamlichi · 1 Sep 2018 at 03:17

ilc72 said:
The Skylake X chips do run hot I’m afraid and the cooler has the slightly noisier SP120 fans but glad you found the solution. Sometimes the thermal paste can get a bit dried out but suggest for longevity to get a cleaning cloth out and apply some Thermal Grizzly Kryonaut paste, also with Skylake X make sure you apply the thermal paste properly as it’s a big processor die. Have a look out for Gamers Nexus videos on YouTube as they give good instructions on the process.

Thanks I think the main issue was that it was not seated properly. I will check out the video for sure. Yes the fans are so noisy!! Can you recommend me any 120 x 120 x 25mm replacement fans? Thanks.

doyll · 1 Sep 2018 at 11:13

What you are experiencing is common. CLCs like you have need lots of airflow through their cheap radiators to cool, and high airflow means more noise. A good air cooler would have cost less money, had as good or better cooling and been much quieter as well. But you have what you have.

A big part of the problem may be your case fans. The stock 200mm front intake only makes 0.996mm H2O static pressure at full speed, which is about 2/3rds what I consider acceptable for case fans to be able to move needed airflow through grill and filter. This means your radiator fans have to work harder and are also probably pulling heated air coming off of GPU up and out through radiator.

Could you remove side cover and run system so we can see if temps are lower with radiator fans spinning slower?

If this helps, I suggest the below solution:

Remove all PCIe back slot covers. This greatly improves rear vent area for better front to back airflow around GPU whiich means lower temps. Get 2x PH-F140MP and install as front intake fans to flow cool air to GPU and up to radiator and 2x PH-F120MP for bottom 120mm intake fans to flow cool air to GPU. PH-F140MP and PH-F120MP are some of the best fans made and OcUK has both on special in 2-packs. PH-F140MP are £16.26 for 2-pack (£8.13 each) and PH-F120MP are £14.99 for 2-pack (7.50 each).
https://www.overclockers.co.uk/two-...140mm-fan-radiator-performance-bu-003-pt.html
https://www.overclockers.co.uk/two-...120mm-fan-radiator-performance-bu-002-pt.html

If you want things even quieter and the stock radiator fans cool at 1/2-2/3rd speed, changing radiator fans to PH-F120MP will lower noise even more. But this will only work if stock rad fans can keep CPU cool at 2/3 -3/4 speed.

Even if you were to change back to air cooling you would need this basic case airflow setup.

Rachid Khamlichi · 1 Sep 2018 at 11:37

doyll said:
What you are experiencing is common. CLCs like you have need lots of airflow through their cheap radiators to cool, and high airflow means more noise. A good air cooler would have cost less money, had as good or better cooling and been much quieter as well. But you have what you have.

A big part of the problem may be your case fans. The stock 200mm front intake only makes 0.996mm H2O static pressure at full speed, which is about 2/3rds what I consider acceptable for case fans to be able to move needed airflow through grill and filter. This means your radiator fans have to work harder and are also probably pulling heated air coming off of GPU up and out through radiator.

Could you remove side cover and run system so we can see if temps are lower with radiator fans spinning slower?

If this helps, I suggest the below solution:

Remove all PCIe back slot covers. This greatly improves rear vent area for better front to back airflow around GPU whiich means lower temps. Get 2x PH-F140MP and install as front intake fans to flow cool air to GPU and up to radiator and 2x PH-F120MP for bottom 120mm intake fans to flow cool air to GPU. PH-F140MP and PH-F120MP are some of the best fans made and OcUK has both on special in 2-packs. PH-F140MP are £16.26 for 2-pack (£8.13 each) and PH-F120MP are £14.99 for 2-pack (7.50 each).
https://www.overclockers.co.uk/two-...140mm-fan-radiator-performance-bu-003-pt.html
https://www.overclockers.co.uk/two-...120mm-fan-radiator-performance-bu-002-pt.html

If you want things even quieter and the stock radiator fans cool at 1/2-2/3rd speed, changing radiator fans to PH-F120MP will lower noise even more. But this will only work if stock rad fans can keep CPU cool at 2/3 -3/4 speed.

Even if you were to change back to air cooling you would need this basic case airflow setup.

That is incorrect they are loud even at low speeds. I am getting 25-29c now at 55% speed, but they are just ... loud

The stock case fans are very quite

doyll · 1 Sep 2018 at 12:54

Rachid Khamlichi said:
That is incorrect they are loud even at low speeds. I am getting 25-29c now at 55% speed, but they are just ... loud

The stock case fans are very quite

LOL
I stand corrected.
I was trying to be nice.
I probably hate CLCs much more than you do, but you are catching up.

is 25-29c with side cover off or what? Why are your temps now so much lower than before?

Your CLC at 55% is making a little louder than a top tier cooler at 100% .. and most of us on air rarely run above about 70% (1000-1100rpm @100% CPU load @ 60-65c depending on CPU, overclock, case fans & cooler being used). And that does not even take into account the noise made by pump and/or water/air bubbles in a CLC.

Indeed stock case fans are probably very quiet. They also are moving very little air. The 200mm front intake is only running 800rpm at full speed making less than 1mm H2O pressure .. while typical front grill and filter have about 0.7-0.8mm H2O of resistance (not really a way to measure resistance) .. case front intake venting has almost as much resistance to airflow as your stock case fan is capable of overcoming .. end result is very little airflow, air inside of case heating up, CLC fans running faster trying to keep CPU cool .. making more noise, with problems going on and on and on.

Ghia · 1 Sep 2018 at 13:18

Rachid Khamlichi said:
That is incorrect they are loud even at low speeds. I am getting 25-29c now at 55% speed, but they are just ... loud

Cooling vs noise is always a trade-off, i.e. each user must decide for him/her-self how much noise is acceptable to achieve efficient cooling. Having the right fans for the job is essential. If you are not satisfied with the noise of your radiator fans, then change them to something better...fans that will keep your CPU cool with a minimum of noise. At the moment, I think the Noctua NF A12x25 PWM is the best choice. They achieve excellent cooling, while keeping quiet doing so. Max speed is 2000rpm, with included Low Noise adapter mounted the rpm is capped at 1700 and even less noisy. They are a new generation of fans, not pretty but who cares as long as they deliver ? If I were you, I'd get 2 of those and get rid of the original rad fans or use those somewhere else in the case.

andicole0 · 1 Sep 2018 at 13:23

I think I'd disagree with the early posts here, for an AIO the idea is the get the air over the radiator as cool as possible so normally I'd blow cooler air from outside into the case. Blowing air our over the radiator will warm the radiator!. Just make sure you have enough air flow to keep the GPU cool.
Andi.

doyll · 1 Sep 2018 at 14:14

Ghia said:
Cooling vs noise is always a trade-off, i.e. each user must decide for him/her-self how much noise is acceptable to achieve efficient cooling. Having the right fans for the job is essential. If you are not satisfied with the noise of your radiator fans, then change them to something better...fans that will keep your CPU cool with a minimum of noise. At the moment, I think the Noctua NF A12x25 PWM is the best choice. They achieve excellent cooling, while keeping quiet doing so. Max speed is 2000rpm, with included Low Noise adapter mounted the rpm is capped at 1700 and even less noisy. They are a new generation of fans, not pretty but who cares as long as they deliver ? If I were you, I'd get 2 of those and get rid of the original rad fans or use those somewhere else in the case.

While I agree there is a correlation between cooling ability and noise, that is only one part of it.

These CLC radiators are the cheapest, lowest quality, worst efficiency made .. and it doesn't matter what fans are on them, they are not going to cool as well or as quietly as better quality/more efficient radiators or a good air cooler will.

The reason they have such high speed fans is to move the higher volume of air needed to get them to cool. Changing to better fans might lower noise a little, but these CLC radiators are simply not efficient and will not cool well without lots of airflow and that means noise.

So Rachid Khamlichi can speed £60 for top tier fans like NF-A12x25 PWM to lower the noise a little but not have as much cooling ability .. still need case fans .. and still not cool as well as if you were to buy something like PH-TC14PE (one of the best)on sale for £49.99.
https://www.overclockers.co.uk/phanteks-ph-tc14pe-cpu-cooler-black-hs-009-pt.html

But Rachid Khamlichi will need good case fans.

andicole0 said:
I think I'd disagree with the early posts here, for an AIO the idea is the get the air over the radiator as cool as possible so normally I'd blow cooler air from outside into the case. Blowing air our over the radiator will warm the radiator!. Just make sure you have enough air flow to keep the GPU cool.
Andi.

Age old argument. Sure, using radiator as intake lowers the temps on component/s it's cooler .. but it increase air temp that is going to everything it's heated air is coolng.

No, blowing air over the radiator does no warm the radiator .. at least not enough for us to even be able to measure the minute amount of friction and resulting increase temp it creates.

Liquid cooling systems are not near as sensitive to air temp changes as air cooling systems.
Liquid cooling takes several degrees warmer air to increase component temp by 1c.
With air cooling 1c warmer air results in basically the same 1c increase in component temp.

So it makes more sense to use radiator as exhaust on systems where other components are being air cooled instead of making other components run hotter just to cool one.

With good case airflow a 240mm radiator in top can be intake or exhaust with little difference in component temps .. but there will still be some cost/benefit involved .. with rad exhaust CPU temp will be slightly warmer and GPU cooler both at full load .. or radiator intake CPU is cooler but GPU will be higher temp with both at full load.

doyll · 1 Sep 2018 at 15:39

dbl post

Ghia · 1 Sep 2018 at 15:53

doyll said:
While I agree there is a correlation between cooling ability and noise, that is only one part of it.

These CLC radiators are the cheapest, lowest quality, worst efficiency made .. and it doesn't matter what fans are on them, they are not going to cool as well or as quietly as better quality/more efficient radiators or a good air cooler will.

No doubt about that :-)

doyll said:
The reason they have such high speed fans is to move the higher volume of air needed to get them to cool. Changing to better fans might lower noise a little, but these CLC radiators are simply not efficient and will not cool well without lots of airflow and that means noise.

So Rachid Khamlichi can speed £60 for top tier fans like NF-A12x25 PWM to lower the noise a little but not have as much cooling ability ..

The better fans would push more air with less noise than what he has now, and still keep the same cooling ability. In fact, with more efficient rad fans he could probably even get it at lower rpm.
I'm just saying that this would be easier than to change all his case fans. Those are running quiet, he says....the problem is with the rad fans. So there might even be room for a small increase in case fan speed without an audible increase in noise ?

doyll · 1 Sep 2018 at 17:45

Ghia said:
No doubt about that

The better fans would push more air with less noise than what he has now, and still keep the same cooling ability. In fact, with more efficient rad fans he could probably even get it at lower rpm.
I'm just saying that this would be easier than to change all his case fans. Those are running quiet, he says....the problem is with the rad fans. So there might even be room for a small increase in case fan speed without an audible increase in noise ?

No, NF-A12x25 PWM simple does not have near as much airflow or static pressure as his stock CLC fans have.

Maybe a little simple math will help.

At full speed CLC's stock fans are rated something like 73cfm and 37.7dB open air and 3.9mm H2O static pressure at 2700rpm full speed

NF-A12x25 PWM are rated 49.73cfm and 22.6dB open air and 2,34mm H2O static pressure at 2000rpm full speed.

That translates into NF-A12x25 PWM having only about 2/3rds as much airflow and mmH2O as the stock CLC fans, both at full speed.

Slow down the stock CLC fans to 2000rpm and wiill not quite as good as NF-A12x25 PWM they will still be similar performance with NF-A12x25 PWM being a little quieter, but not by much.

But that is only 2/3rds as much airflow and CLC will not cool as well on 66% as much airflow as it will with 100% airflow.

Not to take this as step farther, If we put the extreme high performance fans on a top tier air cooler it will be as loud as CLC but give significantly lower temps. There are tests proving this, one being H100, Silver Arrow SB-E (normal fans) and Silver Arrow SB-E Extreme (hi-performance fans)

Silver Arrow SB-E, Silver Arrow SB-E Extreme vs H100
I7 [email protected] Temperature in Delta
Cooler . . . . . . . . . Delta . RPM . RPM . dB(A) . Fans
H100 . . . . . . . . . . 41c . . 2500. . . . . . . 55 . . . . 2x
SA SB-E. . . . . . . . 42c . . 1000 & 1300. 38 . . . . TY-150 & TY-141
SA SB-E Extreme . 34c . . 2500 . . . . . . 56 . . . . 2x TY-143
H100 is 1c cooler than Silver Arrow SB-e but makes more than 3 times the noise doing it
Siver Arrow SB-E Extreme is 7c cooler with fans making similar amount of noise as H100 does.
PC-Cooling video review above data came from:
https://www.youtube.com/watch?v=q6xrsuPwDbo

Another was testing done on TRUE Spirit 140 Power and NH-D14 with TY-143 hi-performance fans at 1200rpm and 2500rpm TY-143 at 1200rpm performs the same as stock NH-D14 fans at full speed or TY-147A on TRUE Spirit 140 Power at 1200rpm. You can see they both give is 8-9c lower temps in below graph. These tests were done on i7 [email protected] so a hot running CPU.

https://www.overclock.net/forum/22111036-post22.html

You can see how much the cooling is improved by the hi-performance TY-143 fan.

Ross Thomson · 4 Sep 2018 at 16:07

have the fans as an intake to cool the rad properly. Your fans are quite loud as standard plus any obstruction in front of the fans will make more sound. Remember that the cpu won't run any better at 60c than it will at 80c at the same frequency.