The Corsair SP (Static Pressure), AF (High Airflow) 120/140mm Fan Review
by E. Fylladitakis on November 25, 2015 8:00 AM ESTCorsair's 120mm Performance
The AF120 Performance and AF120 Quiet Edition
First one up is the 'High Airflow' variant of the 120mm line (non-LED), which comes in Performance and Quiet modes. This is the Performance variant pressure/volume response at 12V and 7V:
Whereas the quiet model has this response - note the axes are the same for both AF120 models in this case.
While both AF120 fans in the graphs above share the same shape and design, with the only difference being their rotational speed, the performance curves are of similar shape but different magnitude. The performance of the AF120 fans is low when the impedance is very high but their volume flow capacity greatly increases when the airflow impedance falls below medium levels.
The SP120 Performance and Quiet Edition
As we move onto the Static Pressure line of fans, featuring fewer but wider fan blades (only 7 vs 11), the expectations lie in higher airflow in high-impedance (dense liquid cooler) scenarios. First up, the Performance model at 12V and 7V:
The Quiet model has reduced fan speeds, which gives a very different graph:
The performance of the SP120 is obviously much different than the AF120, as expected, but is also very different from the performance of the SP140 LED as well. The Performance Edition of the SP120 has an outrageous maximum speed of 2300 RPM and our instruments recorded an outstanding static pressure of 3.42 mmH2O at that speed. The curve declines sharply, with the SP120 displaying mediocre airflow gains as the airflow impedance decreases. It also has a significant stall area within the medium airflow impedance region.
The SP120 Perfomance and AF120 Performance Comparison
As the speed of the SP120 Performance Edition at 7 Volts and the maximum speed of the SP120 Quiet Edition coincide, it can be noticed that the two fans have an almost identical performance curve when operating at the same speed. This is natural as only the rotational speed of the fans differs, the design of the fan itself is identical. But when we compare the SP120 and AF120 variants to each other, we get the following (again, at 12V and 7V)
And in the Quiet versions (note, different axes):
The above two comparisons between the Performance and Quiet versions of the SP120 and AF120 respectively are somewhat unfair. From just a quick look at the graphs, it appears that the SP120 outperforms the AF120 under almost any conditions when both fans are operating at their maximum stock speeds. That however is not correct, as the SP120 versions have a much higher top speed are are in both cases louder. With both the AF120 and the SP120 running at the same speed (and similar noise profiles) we got the following performance curves.
With both fans running at the same speed, the advantages and disadvantages of each design become more apparent. The AF120 provides higher air volume flow in low airflow impedance setups while the SP120 can maintain higher air volume flow levels when the airflow impedance is high. Strangely, even though the SP120 is moving considerably less air while entirely unobstructed, it generates about the same level of noise as the AF120. We can only assume that the large blades of the SP120 generate a very turbulent air flow.
Facebook
Twitter
RSS
92 Comments
View All Comments
toxinate - Thursday, December 3, 2015 - link
BS in Computer Engineering from Rutgers, represent!I just hope you're right, lmao
AntiLumo - Sunday, December 6, 2015 - link
Hey Hulk,I haven't even thought of getting any kind of degree on anything, yet I still use word impedance to describe the flow resistance of helium mixture flowing inside mechanical parts and I do it daily at work. In physics it is quite normal thing to use word impedance, because you can't just say flow resistance since there are so many things affecting the flow resistance and as you can see it's much longer term than impedance.
Probably it would be fine to use the term "head", but I think that is largely used in technical papers and not in review texts meant for common people and I think that the graphs with impedance are nice and clear.
And E. Fylladitakis is not being rude at all, he is just explaining how things are done in this review.
ImSpartacus - Wednesday, November 25, 2015 - link
I don't come to Anandtech for this passive aggressive condescending horseshit.Before today, I was able to say that I've never seen an Anandtech writer snap at a commenter regardless of how coarse they were. You just broke that streak for me. I'm pretty disappointed and a little upset.
Let's be 100% clear in that the content of your post can be completely correct (it seems to be) and the post is still unacceptably rude.
I come to Anandtech to learn new things and I absolutely love to see its writers present new ideas. I don't want that to ever change. However, I don't come to Anandtech to see its writers be appear rude to readers even if those readers are rude "first".
It's really hard to accomplish that because it's so easy to be accidentally appear ruder than you intended - that's just the nature of the limitations of written communication. You really have to go overboard to make sure that your comments can't be misinterpreted.
I'm just concerned because Anandtech has historically been so awesome at that and I don't want that to change.
E.Fyll - Wednesday, November 25, 2015 - link
I am sorry if you, or anyone else, is offended in any way. I certainly did not mean to offend anyone. It just appear to me as common sense that someone who is studying mechanical engineering would not have heard of the term mechanical impedance, except if he/she was a first or second year student. That is why I took my time to explain the difference anyway.Hulk - Wednesday, November 25, 2015 - link
E. Fyll,Holy crap! Your post wasn't rude at all!!! It was informative and your informed opinion. That's what we're supposed to do here isn't it. Are so we politically correct that we can't even politely disagree. And your post was TOTALLY polite. As you can see from my post I also have a different opinion, but it's just that an opinion. There was no mocking or personal attacks here until the person who was so "offended" by your response posted.
Please, please, please, don't apologize when there is no need. We need to have just a little free speech don't we? Can't we discuss and...yes, God forbid sometimes disagree, and in the end learning something? I learned that fluid resistance is also impedance. That's cool and that's why I'm here.
Let's be active and engaged, let's argue sometimes, let's laugh sometimes, but please let's not be afraid to freely honestly express ideas and opinions!!!
Manch - Wednesday, November 25, 2015 - link
Oh hell... here we go... there will be protests, a demand for E. Fylladitakis firing, and a creation of a "safe zone" comments section...That poster must be from that college in Missouri...
Kutark - Thursday, November 26, 2015 - link
Seriously. People literally INVENT things to be offended by these days.tim851 - Wednesday, November 25, 2015 - link
No worries, dude. Your reply was fine.ninjaquick - Wednesday, November 25, 2015 - link
I don't come to anandtech to read shitpost comments by butthurt intertards.Kutark - Thursday, November 26, 2015 - link
<3