ASUS P5B-Deluxe; Problems & Fixes

[Big.Wayne]

one for the CPU (as long as you are using a CPU fan with a 4-pin header e.g. stock with most CPU's)

I have a 120mm Sharkoon '2000' cooling my processor and three 80mm Sharkoon '2000' cooling the chassis.

The 80mm fans are being slowed down by the Q-Fan thing to about 1300rpm which makes them all pretty quiet, however the 120mm fan always runs at full blast?

All the fans are three pin so I wonder why Q-Fan can't work its magic on the CPU fan?

I see it has a 4-pin header (PWM) connection but that should make the Q-Fan work a bit more accurately than a 3-pin, it shouldn't mean a 3-pin can't have its speeds adjusted at all?

Anyone got a 3-pin fan to work with Q-Fan on the CPU header?

[Lou Snutt]

All the fans are three pin so I wonder why Q-Fan can't work its magic on the CPU fan?

I see it has a 4-pin header (PWM) connection but that should make the Q-Fan work a bit more accurately than a 3-pin, it shouldn't mean a 3-pin can't have its speeds adjusted at all?

Anyone got a 3-pin fan to work with Q-Fan on the CPU header?

Bad news, I'm afraid. The CPU fan can be controlled ONLY via the 4th pin. If you want to control the speed of your 3-pin CPU fan then you will have to connect it to one of the CHA-FAN 1, 2 or 3 connectors and set BIOS to ignore the CPU fan warning. This is how I am running the 120mm Noctua on my Scythe Ninja cooler. I haven't tried this with Q-fan running as I let Speedfan control it all.

[Big.Wayne]

Bad news, I'm afraid

Yup I realised that about 6 months ago, just wanted to find out why?

I haven't tried this with Q-fan running as I let Speedfan control it all.

Thats cool? you use Speedfan to control the case fans? didn't think of that

[Lou Snutt]

Yup I realised that about 6 months ago, just wanted to find out why?

Thats cool? you use Speedfan to control the case fans? didn't think of that

Why comes from the different methods of speed control between 3 and 4 wire fans. 3-wire fans are controlled by varying the effective voltage on the 12V wire (usually by PWM). A 4-wire fan has the 12V wire tied to the 12V supply and the control is managed internally within its associated electronics according to the signal input on the 4th wire.

I'm lucky with my Antec P180 case and Ninja cooler that I can fit a 120mm fan on the Ninja to pull air across the RAM and then across the CPU and there is a rear case fan directly in line to take the air out of the case. So by using Speedfan to control these 2 fans depending on the Core 0 and Core 1 temps the whole system is suitably ventilated.