Sapphire HD4850 toxic fan-control

[j4cky333]

Hey,

I have got a Sapphire HD4850 toxic and its fan (zalman vf-900-cu) is always spinning with the same speed (independant of temperature or clock). It is very noisy. As a result I flashed the bios (RBE and winflash) of that graphic card with different fan settings. For example I set "Tmin" to 60°C and "Duty cycle min" to 0. I tried several settings but the fan speed didn't change after flashing.
It runs always with about 1800rpm. I don't know where my mistake is or if it is even possible to reduce the fanspeed of that card with a bios flash.
On request I can post some further information and pictures.

I am thankful about every help.

[boogah]

duty cycle min to 40
T min to 45

make sure you have pwm ramp checked on the bottom

It will run at 40% until it hits 45 then ramp up n down depending on temperature from there.

[tigger]

I changed the fan on my vf900-cu to an 80mm akasa amber,much quieter.

[herve]

Hi,

I did the setup according boogah advises, but it does'nt work. Fan is still runnig at 1800rpms
Is there anyone to help me ?
thanks

[Psyon]

I guess u didn't read the techpowerup review about the toxic card, did you?

http://www.techpowerup.com/reviews/S..._Toxic/25.html

Sapphire has chosen to remove the temperature based fan control mechanism from their cooling solution. The fan will always run at the same speed, no matter if you run an idle system in Antarctica or under full load in the middle of the Saudi Desert. When asked, Sapphire replied that they "noticed that on many systems the problem is that the fan always starts and stops - at different temperatures. So we decided to always run at the same quiet fan speed".

This approach results in one of the noisiest cards under idle. When compared to the reference design HD 4850 the fan is 16.4 dbA noisier in idle - that's over 40x the sound pressure. Under load the margin gets smaller, yet the card cannot compare to the reference design when it comes to fan noise. However, the increased fan speed results in much lower temperatures and higher overclocking potential. Unfortunately power users won't be able to adjust the fan via any software. No matter what fan speed the card wants to run at the fan will always be around 1700 RPM.

You will not be able to control the rpm with bios or software. The only way to control it is to use fan controls like zalmans fan mate. For me its the main reason I don't buy the toxic card. Even though its overclocking capability is great.

[herve]

Unfortunately for me, your right, I didn't read it...
If I had thought, I would not buy it..
hopfully I have one zalman fan mate....

thanks for your reply.

[DonInKansas]

I presonally always ran my Zalman at 100%...It's so quiet I saw no reason not to.