i BELIEVE THIS AIRFLOW THING IS A MYTH!
Anyhow the power supply fan produces some airflow which is effective enough(It is a real airflow).The intake fans for example produce more turbulence than airflow...and don't forget the noise!
For example either I have my case open or closed I cannot take my processor higher....or maybe 2-3% higher.Is it worth to become deaf just for slightly higher overclocking?It is a personal choise of course but I think the companies just want us to spend as much as possible on unnecessary gadgets such as fans....
With only one fan@2000 rpm I have overclocked my processor 1700PR@2002 Mhz (48-49 full load) and it is nearly silent.What would some extra fans offer me?And believe me there is airflow created by the other 2000 rpm fan of the power supply.Imagine that it can easily suck a light piece of paper from the intake slit.
In my opinion it is all a matter of bad and mainly rushed technology.Instead of placing heat issues as apriority they mainly consider speed.If they invested a bit more they could produce fanless systems.I mean what the hell!My stereo gets so hot on the back side, I could fry an omelette on
I can imagine the temps inside...but they didn't add 4 intake and 4 excaust fans to keep it cool! My monitor also gets extremely hot,so what.My washing machine too