So you see the Tough Fan 12, it has the second highest Pressures, but its performance is abysmal. The only reason this can happen is if its flow characteristic is severely at odds with the heatsink geometry.
It's the best explanation that there's simply no way to correlate CFM or Pressure to performance, because such a huge interaction gap could occur.
The $32 noctua A12, another noise optimized fan, does quite badly, AS BADLY, as the $7 noise optimized P12.
The community is divided, but it's been aware for a long time that Noctua A12s are bad performers, but people are willing to trade that for noise. Which is when Arctic came in with the Disruptive P12 for $7, which is also low flow, noise optimized.
We know a12 and p12 are both very quiet fans, they also move the least air, less flow, less noise > perform badly.
The T30, kind of makes a case for thicker fans, it's 30mm, But there's also way cheaper 30-38mm fans, Antec/ Server fans. The trouble is Ball bearings on the later which will always chatter.
The case for thicker fans, seems to be more Pressure at lower CFM, but what does that do, it's not simply pushing the air, it's probably just generating more turbulence, and that probably makes the difference when heatsink interaction comes into play. It matters at these non-loud rpms.
Up until 1800 RPM is the most important range, anything after is going to be noisy, so REALISTICALLY, 1800 is the battleground.
