using smcfancontrol, question

is there a reason why 2,000 is the default rpm for the fans?

in other words, is it bad for my mbp fans to be set at 5,000 instead?
i suppose it puts more wear and tear on the fans but should this be any concern?

 

I would say don't set your fans at default 5000 RPM. It will probably be a problem in the long run. I personally set my fans at 3600 RPM.

 

why set your fans even at 3600? isnt it pretty loud at that point?

 

Nope, that fans don't start making noise until right around 4k rpm. I have my fans set to spin at 3600rpm when plugged in, and there's no audible difference.

 

Do you have some kind of heat problem?
If not, then don't raise the speed much (or at all). The components don't last much longer even if you drop the temp a few degrees, and the fans will fail much sooner, being the lowest quality components in there. They're just not built for constant max speed. On top of that you'll see your battery life drop a bit.
If you do have a real heat problem like the cpu running 100°C (212°F for those in less civilized parts of the world) or something like that, then the answer isn't raising the fan speed either.

I just don't see why you would want to run the fans so fast anyway...

 

I have applecare so if the fans go out, they get replaced. And I only raise the fan speed when I'm plugged in, and it drops the temperature down about 5 degrees C.
You need to set a speed in smc if you want the fans to spin at anything but default in Windows(at least with the boot camp beta, did they fix that with Leopard?).
So if I'm playing HL-2 and my fans are only spinning at 2k rpm, there's gonna be a huge issue with heat.

 

Actually, its barely noticeable. For me, at least. Any higher and then I start hearing the fans a lot. But at 3600 RPM, I can keep my MacBook at around 40-50 C, whereas at default 1800 RPM it stays around 60 C.

 

I hear the difference between 2000 and 2500 rpm very distinctly.... maybe I'm just sensitive.

I understand the bootcamp/hl2 issue, the other rationales are suspect, IMO.
Everything in the lower case is designed and built to run at these temps (and higher). Fan failure, OTOH, is a bad scenario, with temps going runaway pretty fast with possible component failure.

The reason for 2000RPM being default is fairly probably that it's the lowest speed (and lowest noise) at which the fans are giving decent airflow. The airflow does not increase in direct relationship with fan speed (due to complex issues with inlets/outlets, blade design and pressure rise).
Centrifugal fans like those used in laptops are good at maintaining pressure, but quite limited at increasing airflow, so that when you just jack up the speed they increase airflow a bit, and increase noise, power consumption and wear alot.
It's all a compromise. The fans in the MBP are probably designed for best efficiency at around 2000RPM (possibly a bit higher, but probably under 3000RPM)

For Win/HL2 5000RPM is probably a good bet.

I'm not a true expert on the matter, but know a bit about fans, impellers and airflow.