Originally Posted by
Webby
On the whole the Yate loons are speced right so if they say 80cfm they will do that in free air (I won't go into the whole free air against in case ratings surfice to say a fan in a case will not achieve its rated value for airflow) so fans which are the same dimensions and have similar design will have similar flow rates for the same rpm.
As to monitoring fan speeds if the fan has a 3 pin connection it will have speed monitoring, if it has 4 pins and is a PWM it will still have rpm monitoring, a 4 pin (molex) connector will not have rpm monitoring.
I would go for the Yates or more Xilence probably lean towards the Xilence as they will sound the same as the ones you already have which will make it sound quieter (fans with different sounds will sound louder in combination than all the same).
As for the thermaltake fan you listed above the cfm is probably about right for a 2000rpm 120mm fan but the noise level is well off it is more likely going to be 35 - 40 dB.