Asus Sabertooth 990fx and non-pmw fans

Is it possible to hook up non pwm fans and allow the bios to control them?

Should provided it's a 3-pin FAN. If it is then the MOBO will just use voltage regulation for speed control.

the manual says that the cpu fan must be pwm.

Could someone who has tested it let me know?

um.. it's not like it WONT work at all, try it..

"Is it possible to hook up non pwm fans and allow the bios to control them?" = That is too general a question.

If you asked, can non-PWM fans be used on the fan headers besides the CPU, the answer would be 'yes'. It is also true that the manual for that motherboard specifically defines the CPU cooling header as a PWM header. Further it is close to 100% accurate that most of the better known and most reviewed HSF assemblies have PWM fans bundled with the HSF since the HSF manufacturers know that the CPU header for practically any newer motherboard will use a PWM style fan. That about covers the current situation.

That answers half of my question, but will the Bios be able to dynamically control the speeds of each fan that is not PWM and connected to the headers other then the CPU.

Watch this video carefully, i think it will answer your question
Overview of 900 series MBs

tangletail said:

That answers half of my question, but will the Bios be able to dynamically control the speeds of each fan that is not PWM and connected to the headers other then the CPU.

Click to expand...

Yes. Any 3 pin fan connected to a PWM header on the mobo will be controllable via the bios. Certain fans just plain won't start up with less than 50% of their rated power though.

Is there a special reason why the CPU fan headers only support 4 pin fan control, the 4 pin chassis fan ports on the other hand can support 3 pin fans with voltage control? I thought 3 pin fans were still pretty common, my Noctua dual fan cooler for example has only 3 pin fans and it's not that old? Maybe, the problem here is that I have only used Gigabyte Boards for years, which all had a setting in BIOS: CPU fan control mode - Auto/PWM/Voltage.