Like many people, I used to manually control the GPU fan. I turn up the speed for gaming and turn down the speed for quiet computing. The problem is I have to remember to do it every time before gaming. This soon becomes a chore and sometimes I do forget. Recently, I figured out how to put it in auto-pilot mode, which similar to the Cool'n'Quiet feature on AMD CPUs. The result is fantastic.



Everytime GPU temp goes above 43, fan ramps up. When the temp drops, fan slows down. No more manual work. This is magic. I love it.



=== Hardware & Software Used ===
- Chaintech VNF4 Ultra (or any nForce4 board with Phoenix Award BIOS)
- Zalman VF700 (or any GPU fan with a standard 3-pin fan connector)
- SpeedFan 4.25 (http://www.almico.com/speedfan.php)



If you have an nForce4 board with Phoenix Award BIOS, the steps described here should apply to your board too.

I have a Chaintech nForce4 Ultra board with Award BIOS. I have heard that the design of this board is closely followed to AMD's reference board. So the features on this board should be available on other nForce4 boards too.



=== BIOS Settings ===
Change or verify the following settings in the BIOS.



1) If you have Cool’n’Quiet enabled, both CPU fan port and case fan port will be in Auto mode by default. I like the result of Cool’n’Quiet, so I leave the Cool’n’Quiet enabled.



2) Go to the PC Health Status menu from the main BIOS menu, then go to Fan Speed Control.



3) Change Case Fan Control from Auto to Disabled.

When in Auto, the VF700 fan is off when booting, it won’t be on until WinXP is up and SpeedFan starts running. In Disabled mode, the fan port will be on during boot and SpeedFan will lower the fan speed when the program is loaded.



=== Test your fan ports ===
It is easy to test the fan ports.

1) Dowload and install SpeedFan 4.25
http://www.almico.com/speedfan.php



2) In SpeedFan 4.25, set Fan2 to Software Controlled.

3) Plug any case fan with a standard 3-pin fan connector to fan port 2 on your motherboard. (To avoid the risk of overheating your GPU, do NOT use your GPU fan for testing.)



4) Change the fan speed from SpeedFan.

5) If fan port 2 is not controllable, try fan port.3, then fan port 4 on your motherboard.

6) If none of the fan ports are controllable, now go to step 2 and set Fan3 in SpeedFan to Software Controlled, and repeat steps 3 through 5.




If you have found a controllable fan port, congratulations! Now plug your Zalman VF700 (or any GPU fan)’s 3-pin fan connector to the controllable fan port on the motherboard.



=== Software Settings ===



1) In SpeedFan 4.25, make sure Fan2 (maybe Fan3 on your board) is set to Software Controlled.



2) Set the Zalman VF700’s fan speed between 25% and 100% and auto variated.



3) Uncheck all the fans not controlling CPU and GPU. So only Fan1 is checked for CPU, and only Fan2 is checked for GPU.

If you are using an nVidia 6600GT card, then the Remote Temp on MAX6648 chip is the GPU temp, and the Local Temp on MAX6648 chip is the 6600GT board temp.



4) My Remote Temp is always 5C lower than the one shown in nVidia’s nV-Monitor, but it is easy to adjust the offset.



5) Then I set the desired GPU Temp (Remote Temp) to 43C and warning temp at 55C. (The latest version 4.25 supports events, which can beep, execute a program, or popup a message to alert you in case the CPU or GPU overheats or a fan fails, etc. You can add events on the events tab.)



6) I changed the “Dalta value for fan speed” from 10 to 5. When in 10, SpeedFan rams up and down at 10% at each change. 5% is smoother yet still fast enough. Also, check the "Minimize on close" checkbox, becuase you don't want to turn off this "Auto-Pilot" by accident.


Now try some games and watch or hear the fan ramping up and down on its own. =)


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This guide is based on the post I wrote about cooling the nForce4 Chipset. ( http://forums.silentpcreview.com/viewtopic.php?t=24846 ) I don’t overclock, so the Chipset temp doesn’t vary as much as the temp on GPU. Therefore, This SpeedFan technique is much more suitable on a GPU fan. Now I hang a PanafloL1A running at 7v above the chipset, and the chipset temp never went above 42C.

Create a shortcut for SpeedFan and drag it into your StartUp folder, so the SpeedFan automatically runs when you start windows.