Fans: CFM(cubic feet/meter) vs RPM

[hybrid11]

hey all,

So I was looking to buy a new 120mm fan for my heatsink (Scythe Infinity) and I saw 2 fans (both were 30 dba):
-an Antec one which ran at 2600 RPM and 34 CFM
-another Antec which ran at 2200 RPM but 79 CFM

How come the 2200RPM one displaces more than double the air the 2600RPM does?
In this case, am I right in assuming that the second one would be a better choice for my heatsink?

EDIT: both are 120x120x25.4

 

[1Tanker]

hey all,

So I was looking to buy a new 120mm fan for my heatsink (Scythe Infinity) and I saw 2 fans (both were 30 dba):
-an Antec one which ran at 2600 RPM and 34 CFM (more expensive)
-another Antec which ran at 2200 RPM but 79 CFM

How come the 2200RPM one displaces more than double the air the 2600RPM does?
In this case, am I right in assuming that the second one would be a better choice for my heatsink?

First of all, the low-flow fan is most likely a 25mm thick fan. The high-flow is likely a 38mm thick fan. Thicker bodied fans generally flow more air(more fin/blade surface). Also, fan shape, angle of blades, and number of blades can create different airflow characteristics. Yes, the 2nd option would be better, but will also be louder. GL

 

[hybrid11]

my bad, I forgot to mention that they are both 120x120x25.4 mm, I just realized why one was cheaper though, it didn't have the blue LED
Thanks for the reply!