Help w. CPU Fan speed on ASRock G41C-GS

[deFoRMer]

Hi, all! I'm from Russia, so forgive me for my english.
On this mobo in BIOS, in "H/W Monitor" has "CPU Quiet Fan" option, which activate "Target Fan Speed" profile with 3 possible modes: "Fast", "Normal" (may be "Medium") and "Slow". My CPU fan is PWM compatible and connected to mobo 4pin (CPU Fan) socket.
If i set "CPU Quiet Fan" in "Disabled" (or if i set it in "Enabled" and the "Target Fan Speed" is set on "Fast") my CPU fan rotate ~4500rpm and create a very big noise.
If i set "Target Fan Speed" in "Slow" my CPU fan rotate ~3800rpm and the noise is still very loud.
---
Question: how can i designate to this 3 modes ("Fast", "Medium" and "Slow") another values, that the CPU fan RPM was about ~1200, 1000, 800?

[_JP_]

I have the very same motherboard.
Set the "CPU Quiet Fan" option to [Disabled], then download and install SpeedFan, assuming you use Windows as your OS.
I've been using it for this board to control the fan connected to the CPU_FAN1 header (4-pin, PWM) and it works very well.
Remember that the two other 3-pin fan headers are not controllable (CHA_FAN1 and PWR_FAN1), even though they show up on SpeedFan.
Here's a good guide to setup SpeedFan.