[SOLVED] Can I use both 4-pin and 3-pin case fans?

[Deleted member 2720853]

My case (be quiet! Pure Base 500DX) comes with three stock 3-pin fans. I want to get 3x 4-pin High Speed version of the same fans, since I read good reviews, so I can have two high speed intakes, one high speed exhaust. However I also want the top stock fan to remain as is so I can maintain positive pressure/close to neutral, which is not achievable otherwise. But I'm having doubts here.

I read online that PWM fans do not behave well when a 3-pin fan is also connected.

My motherboard will be a GIGABYTE Z390 Aorus Pro. Will I have any issues if I connect three PWM fans and one non-PWM fan on the top (and have the non-PWM fan run at full rpm all the time)?

 

[Deleted member 2720853]

aside from noise no.
the extra pin is the speed control pin but a three pin fan will work on a PWM header with no speed control, just as a 4 pin PWM will fit on a three pin socket with no speed control.

The full RPM on that top fan will be 900, and it's a be quiet! fan which people have said are silent. Noise does not bother me as long as I have a properly cooled machine anyway, thank you for the response.

 

[Paperdoc]

If I understand correctly, you will remove two of the original 3-pin fans . That will leave you with four case ventilation fans - three new 4-pin PWM type, and one original 3-pin fan.
You are correct that the two types of fans require different settings. But you CAN have ALL of them under automatic control based on the mobo temperature, simply by using the mobo fan adjustment options.

See your manual, p. 15 and 17. You have four SYS_FAN headers - one near the top rear, and a trio at bottom front of the mobo. For simplicity you can connect each fan to its own header. See p. 25-26 to get into BIOS Setup and reach the Main Menu. There choose MIT at the top. See p. 27, select Miscellaneous Settings. See p. 32 for details of options for Smart Fan 5. Each of the four SYS_FAN headers needs to be adjusted individually. First, select the first one and set its options as follows.
Fan Speed Control to Normal.
Fan Control Use Temperature Input to Motherboard, not CPU.
Fan / Pump Control Mode to PWM for all the new 4-pin fans, BUT set this to Voltage for the one 3-pin fan.
Fan / Pump Stop to Disabled
Fan / Pump Fail Warning to Enabled.
Configure each of the four headers in turn. When done, use Esc to return to the Main Menu, then F10 to get to the Exit Menu on p.43. There choose to Save and Exit Setup to save your settings.

Configuring this way will ensure all of the fans can be controlled, and that all will be sent the same control signals so they are synchronized. Becasue the one 3-pin fan is different from the others, it may run at slightly different speeds, but that does not matter.

 

[Deleted member 2720853]

If I understand correctly, you will remove two of the original 3-pin fans . That will leave you with four case ventilation fans - three new 4-pin PWM type, and one original 3-pin fan.
You are correct that the two types of fans require different settings. But you CAN have ALL of them under automatic control based on the mobo temperature, simply by using the mobo fan adjustment options.

See your manual, p. 15 and 17. You have four SYS_FAN headers - one near the top rear, and a trio at bottom front of the mobo. For simplicity you can connect each fan to its own header. See p. 25-26 to get into BIOS Setup and reach the Main Menu. There choose MIT at the top. See p. 27, select Miscellaneous Settings. See p. 32 for details of options for Smart Fan 5. Each of the four SYS_FAN headers needs to be adjusted individually. First, select the first one and set its options as follows.
Fan Speed Control to Normal.
Fan Control Use Temperature Input to Motherboard, not CPU.
Fan / Pump Control Mode to PWM for all the new 4-pin fans, BUT set this to Voltage for the one 3-pin fan.
Fan / Pump Stop to Disabled
Fan / Pump Fail Warning to Enabled.
Configure each of the four headers in turn. When done, use Esc to return to the Main Menu, then F10 to get to the Exit Menu on p.43. There choose to Save and Exit Setup to save your settings.

Configuring this way will ensure all of the fans can be controlled, and that all will be sent the same control signals so they are synchronized. Becasue the one 3-pin fan is different from the others, it may run at slightly different speeds, but that does not matter.

First off yes, you understood correctly. Second, the 3-pin fan has a maximum RPM of 900, while the ones I'm getting have 1600 RPM max. It is why I had no problem with leaving it running at full speed, but now that I know this is possible, I'll give it a shot. I'll connect the 3-pin one on the top header and the 4-pin ones on the trio of headers at the bottom for convenience. Thanks!