Thank you very much for input Ricardo
Well, As mention above, I had a Noctua NH-C14 cpu cooler to work with E8400
The cpu has never exceed 55 Cel even at full load.
The reason that I worry about is the system fan speed, it is run at low speed while the other components are hot.
With this speed, it can only move out a little hot air, this will effect the VGA card performance ( I have tested with a 120mm rear fan running at 1200rpm with fix speed and the VGA run not so hot or noisy). Beside that the X-fi extrem music is also not a cold card
I can let the rear fan always run at this speed(1200rpm) to get the system stay cool but I do not want to loose the fan control ability of DP43BF. This ability will expand the fans' life and keep the system quiet.
My friend ask me " why did you buy the Noctua NH-C14 while you are unable to overclock with Intel mobo?"
And I said: because I need a really cool & quiet system
The only way to keep an eye and probably modify the rear, front and aux fan is if the fans are 4 pin. The system fan headers support auto detection for 4 and 3 pin system fans. If a 4-pin system fan is detected, wire management is used. If a 3-pin fan is detected, liner voltage control is used, no fan control or monitoring. There are other third party options for monitoring and permit full control on each fan individually (software or hardware ). You can do a research on the web with key words like: “fan monitoring and control software” or “thermal temperature LCD display”. If you lined up for a hardware solution try to check with the manufacturer or seller for compatibility first.