how much air should case fans pump?

[eLiu]

How much CFMs?

Ive seen some 41CFM@34db...(80mm), for a mere 3 bucks...also some quieter ones that pump less air

And- those fans with thermal sensor speed control things...u kno, they goto higher rpm @ higher temps. With those, what is generally a good "stepping"? Like is 85C-41CFM, 65C-33CFM...good?

or maybe...45C-43CFM@37db, 40C-39CFM@35db...etc

this is for a 1.2ghz AMD system...will probably OC to about 1.4+, so heat matters (i think)

thanks,
-eric

 

[Jhhnn]

The issue is more complex than your question suggests. It depends largely on what enclosure, how many components and fans, and how much noise you're willing to endure. There's not enough info for a definitive answer.

In general, spending a little more for quality fans is worth it- they are more reliable, longer lived and quieter at the same airflow as cheap fans. Panaflo, Sunon, Adda are good brands, along with some others. Panaflos are the exception to the rule that ball bearings are better than sleeve bearings in commonly available fans.

Of the two temp-controlled fans you mention, the second would probably be a better choice. This type of fan has not found widespread use because they don't ramp up to higher rpm at temps suitable for computer cases. You definitely do not want case temps above 35 degrees C.

 

[cnhoff]

I am quite happy with 4 "weak" 19cfm@12dBA fans, my TBird@1500 stays at around 42-50 full Seti load, and the system is not too loud, also one should not underestimate the combined noise of those fans! After all, you can hardly hear one of those fans, but you can certainly hear all of them!

 

[eLiu]

which HSF do u have on ur CPU? and which case?