Question Radiator Fans - Will I see a huge performance drop (temperature wise) when switching from Corsair ML120 pro to Noctua NF12 or A12x25?

[Bears133]

When looking at radiator fans specifically, do you want to choose the fan with the highest static pressure for the best performance? Looking at the spec sheets, the ML120 pro has a Static Pressure of 0.2 - 4.2 mmH20. The NF-12 has a Static pressure of 2,61 mm H₂O and the A12x25 has a Static pressure of 2,34 mm H₂O.

So I assume you get 4.2 out of the ML120 at max speed which is pretty much double of the noctua's. How does this translate to performance exactly? Will I see a significant temperature gain with the noctua's since the static air pressure is almost half?

I also have an issue with the ML120's I currently have because they can get a bit loud at max CPU load.

 

[rubix_1011]

Static pressure indicates the ability of a fan to push air through restrictive areas, such as radiators or dense cooling fins.

More static pressure is generally ideal for radiators. What you are stating is that using fans with 50% static pressure would perform more ideally, and typically that is not the case for liquid cooling design, unless you have a radiator with very low FPI, like 9-11 FPI.

 

[Paperdoc]

What the Pressure spec of a fan means is that it CAN provide some air flow against a backpressure LESS than that. The fan gives its max air FLOW at max speed against NO backpressure, and less flow as backpressure increases, until at and above the PRESSURE rating you get virtually NO air flow. So, looking at the specs you cited, the two Noctua fans will produce VERY little actual air flow if the backpressure (resistance to air flow through the rad fins) exceeds 2.5 mm water, whereas under those same conditions the ML120 will still blow perhaps 40% of it max airflow rating. This suggests that the Noctua fans you checked out were not really designed for use with tightly-spaced fins, although they are rated higher for max backpressure than fans optimized solely for free-air case ventilation situations. If you really want the high Pressure rating, look further in the Noctua line, because thy have SOME models that exceed 4 mm water pressure. The tough part of this, of course, is that you do NOT know what backpressure the rad you have does present to airflow.

You post title asks a different question, though: Will you see a big change in TEMPERATURE?
Generally, no, BUT sometimes yes. How's that for confusion? We must start by recognizing exactly what an automatic fan speed control system does. It really is a TEMPERATURE control system. For the CPU, it watches carefully the actual temperature inside the CPU chip according to a sensor built into the chip. Pre-programmed into the mobo BIOS is the desired target temperature for that particular chip type. The control system manipulates the speed of the CPU cooling fan to whatever it takes to keep the TEMPERATURE on target. It is not trying to control to a speed target; it is using speed to achieve a temperature target. So if you change the fans involved, with NO change of temperature target, the fan SPEED will be adjusted, but the internal CPU TEMPERATURE will be kept to the same target or very close. Where you DO see a difference is when the system is being used heavily and generating a LOT of heat. In those situations, a poorer-performing fan will end up running at top speed and still not able to keep the temp down as well as a better fan that has more reserve cooling capacity. So better fans give you more ability to work really hard without overheating.

 

[Crosslhs82x2]

I definitely Agree with both.
I can add this though
If you are going to spend the money for Noctua fans then spend it on the right fans.
The following link will have more static pressure and Cfm.

https://noctua.at/en/nf-f12-industrialppc-3000-pwm/specification

I have 1x corsair h100iv2 with those fans.
I also have 2x corsair h110i with 2x 140mm ippc 3000 rpm versions and will not run anything else.
When you need the extra cooling from stress testing or heavy cpu intensive work loads those fans the have what it takes.
I haven't had to replace any of them yet.
Just know if they are loud when at 3000rpm.
The h100i 2x120's is on a fx-6300 and set on quiet mode and 1050 to 1300rpm, Usually i run my 2 h110i's on performance mode which is 1600 to 1900 rpm,
1 is on a fx-8350 oced @4.6g the other is on a r5 2600x oced @4.1g.

https://imgur.com/a/4L1uUVV

View: https://imgur.com/a/4L1uUVV

That was taken in a 80-84f room after 9hrs of Occt stress testing with fans set to max.
Certainly in a cooler room the temps would be much lower and i wouldn't need as much fan but all 3 units are not so lucky.
As far as price they are pricey the 120's ran me about $54.00 for the pair and the 140's ran about $60.00usd a pair from newegg.

I hope something here helped
Good luck !!!!!!

 

[Paperdoc]

The Corsair ML120 PRO PWM fan is a high-performance model very well suited to use on a radiator. Its specs say it runs 2400 RPM max consuming 0.225 A, and delivering 75 CFM airflow max with no backpressure. It can deliver reduced air flow against backpressure of up to 4.2 mm water. At full speed it generates noise at 37 dBA. Warranty is 5 years.

In the Noctua line, the only models with comparable specs are the Industrial PPC line detailed by Crosslhs82x2 above. The Noctua NF-F12 IndustrialPPC-2000 PWM model has specs of 2000 RPM max consuming 0.1A, and delivering 122 m³/hr (72 CFM) max airflow, able to blow up to a max backpressure of 3.9mm water. noise at full speed is 30 dBA, warranty is 6 years. Noctua fans have a well-deserved reputation of long life well beyond their warranty period, but I have no comparable info for the Corsair model above.

So between those two, maximum performance is not much different - small advantage to the Corsair model. However, at max speed the Noctuas are somewhat quieter.

The Noctua NF-F12 ippc-3000 PWM model cited by Crosslhs82x2 has higher performance in all respects, but that also means possibly more noise when they operate at 2000 to 2400 RPM (i.e, less than their max speed and output)

Just to complete the specs comparison, the Noctua NF-A12x25 PWM model does 2000 RPM using 0.14 A, 102 m³/h (60 CFM), 2.34 mm water max, noise at 23dBA. The Noctua NF-F12 PWM dies 1500 RPM using 0.05 A, 93.4 m³/h (55 CFM), 2.61 mm water max, noise at 22 dBA. Neither of those is comparable to the two heavier-duty models above.