What is the normal speed of a fan?

[ViPeRMiMiS]

I hear about fan rpm.
There are many sizes as far as I know (like 120mm etc)
SO I install a 120MM fan... which is 5.000 rpm let's say.
What is the difference with a 120mm fan of 1.000 rpm?
More means better COOLING -BUT- more SOUND? Which is the "normal" speed of a fan?
thanks

 

[slh28]

Stock case fans are usually around 1000prm. Anything above 3000rpm would be very loud, search youtube to gauge the noise levels. I don't think they even go up to 5000rpm...

 

[ViPeRMiMiS]

Stock case fans are usually around 1000prm. Anything above 3000rpm would be very loud, search youtube to gauge the noise levels. I don't think they even go up to 5000rpm...

Thank you very much for the answer
I said theoritical numbers that are not real, just examples
So using a 3000rpm means it is Super Duper effective at cooling but it is very loud? If I use a 1000rpm it means it is Super Duper quiet but it is not as effective as a 3000rpm in cooling? In other words I can OC more with the 3000 than the 1000rpm?
Thanks

 

[slh28]

To be honest I've found that fans don't really make that much difference, maybe 2-3C difference between silent and full power modes. The actual case and airflow is much more important, and the increase in noise isn't really worth the trade off in most instances.

 

[ViPeRMiMiS]

To be honest I've found that fans don't really make that much difference, maybe 2-3C difference between silent and full power modes. The actual case and airflow is much more important, and the increase in noise isn't really worth the trade off in most instances.

Thank you very much for the answer

 

[DKRON]

it depends on which brand (shapes of the fins on the fan) some are known to be better at pushing air more than others

 

[ViPeRMiMiS]

it depends on which brand (shapes of the fins on the fan) some are known to be better at pushing air more than others

thanks

 

[DKRON]

look for "CFN" can't remember exactly what it stands for but its the measurement of how much air it can push so the higher the better (should be atleast 100) for 200mm fans

 

[ViPeRMiMiS]

look for "CFN" can't remember exactly what it stands for but its the measurement of how much air it can push so the higher the better (should be atleast 100) for 200mm fans

Found it , it's "CFM" thanks