RPM SETUP for Case Fan



I have recently installed the chasis fan in the rear of the motherboard. But is kind of little bit louder. I heard if i lower the rpm or speed of fan it can quieter. It is directly connected to motherboard which is p5p800 asus. I want to lower the speed and i checked in the bios but in bios it only shows the rpm and other option is ignore nowhere it shows how to lower the speed. Please let me know how i can lower the speed or can make quieter any other way or in bios itself.
second question i have 3 fans in case two in rear one in front but there is no vent in front where is air can go out so what i want to know is which way fan should be facing.


my m8 asked this a while back so i did him this pic

as for altering the fan speed buy a controller


try speedfan to control your fan speeds and monitor temps.


Now what i did is i got two fans for the case to blow the air out I put it both in the rear of the case cause i have one in the front already. But i changed the direction of front one cause there is no vent in front of case to push the air out. it push the air to rear and rear fans push out. But these are not quiet fan. I have also installed speed fan to check the temp my case has the temp in front as well but speed fan and temp on the front is different in front of the case it tells 44 to 46 even with the new fans installed and on speed fan is 51 -52 with fire icons i guess that means high temp. yesterday i was working on computer just browsing the temp went way too high 70 - 80 and noise of computer went high as well so without turning off i opened side of case left it for 15 minutes everything in the computer was hot hd dvd burner case. I don’t what happened cause i was just browsing on the internet. i have the screen shot of speed fan but don’t know how to post it in here if i can please let me know
i left the side of case open and temp went down to 33 -36 but i don’t know why it did that i just replaced the ide cable for harddrive other then that nothing fans are running for couples of days