This place rocks for info. First build. NZXT Tempest(Airflow King)Case, 6 fans. Asus M3a78-em motherboard with 3 fan headers marked pwr fan , cha fan, cpu fan (obvious). Does it really matter which 2 of my six fans go into the pwr and cha fan headers? The other four will naturally be connected to my PSU molex connectors. Since I'll probably be able to control the two fans connected to the MB, I was going to pick a intake and an exhaust fan. My best guess!
Normally, "PWR" fan headers don't supply power, but just read the RPM's of the power supply fan. I'm not sure if this is the case with your MB (which I just got one of as well). I just left my PWR header unconnected.
Six fans sounds like way too many (and could actually cause airflow problems) -- do you have a wood burning stove inside your chassis?
I spoke with the Asus tech support and have it all figured out. You are correct, the PWR fan header is strictly for the power supply fan. My PSU, a OCZ Stealth X Stream 700W, doesn't have a dedicated connector for the fan, so the header on the Motherboard I've left unconnected. For the CHA fan header, he recommended I connect the rear fan, which I did.
As for my NZXT Tempest (case) and its six stock fans, well the reviews on this baby speak for themselves (check out Newegg). Its not unlike other midrange gaming cases with 4-6 fans. They all work great and are extremely quiet. In fact, I'm blown away by this case and would recommend it to anyone wanting to build a rig. This is my first and it all went together almost too easy!
3.1 ghz AMD Athlon 64 X2 6000
Asus M3A78-EM Motherboard
G.Skill Pi 2X2 GB 4-4-4-12 RAM
Visiontek Radeon 4850 HD video card
Western Digital Caviar Black 640 GB hard drive
Asus 22X Optical drive-burner w/ lightscribe
OCZ StealthXStream 700W power supply
NZXT Tempest gamer case
when the tax return comes in: Acer 22" WG LCD Monitor
Ok, so now I realize I have connected a power source to my PWR_fan connector (but only the left most yetllow and black wire to the 12v and grnd, I missed the rpm pin)
So I am thinking I must have fried something. The computer will not post/boot now if I remove the power connector (leaving the PWR_fan bare or add a chasis fan to it). Not sure why it works if I have the power connected unless it needs the extra power from what I fried.