Mistakenly bought PWM case fans. Options?

Control: management of fans, temp/rpm monitoring via soft/hardware

Moderators: NeilBlanchard, Ralf Hutter, sthayashi, Lawrence Lee

Post Reply
oneleaf
Posts: 5
Joined: Thu Aug 23, 2007 8:54 am

Mistakenly bought PWM case fans. Options?

Post by oneleaf » Fri Jul 29, 2016 4:30 pm

I am sure this happens a lot. Seeing my 4-pin headers on the motherboard, I bought a bunch of PWM Noctua case fans (NF-S12B redux-1200 PWM).

Then, I found they didn't spin up, and some research shows me the motherboard headers are PWM only for the CPU fan, but the others have a different pin-out and are meant to be voltage controlled.

I was wondering what people here might recommend. I am fine getting some manual fan controllers to stick in the case. I think the BIOS also has some options for manually setting a percentage on these fans, so I could do it like this as well, I think. Is there any reason to replace the fans with non-PWM ones? Or is it totally safe and reliable to manually control these?

Generally speaking, is it OK to always buy PWM fans and simply use voltage control when PWM is not available? Or is it important to get the right fan for the right job? Thanks for any advice!

Fire-Flare
Posts: 422
Joined: Sun Jun 13, 2010 12:44 pm
Location: Seattle

Re: Mistakenly bought PWM case fans. Options?

Post by Fire-Flare » Fri Jul 29, 2016 7:10 pm

PWM fans won't be harmed in any way if they're run off a 3-pin header or undervolted.

I don't see why they wouldn't spin on your board, (unless the initial setting is too low?) but I suppose you could use a pointy object to extract the 4th pin and see if they'll work as 3-pin fans.

quest_for_silence
Posts: 5275
Joined: Wed Jun 13, 2007 10:12 am
Location: ITALY

Re: Mistakenly bought PWM case fans. Options?

Post by quest_for_silence » Fri Jul 29, 2016 8:36 pm

oneleaf wrote:Then, I found they didn't spin up
If they didn't spin, maybe the voltage is under 6.5V: try to change the relevant header settings in the BIOS (or use a sw interface if available, like FanXpert or SpeedFan).

oneleaf wrote:Is there any reason to replace the fans with non-PWM ones? Or is it totally safe and reliable to manually control these?

Try: they could have a relatively high minimum speed for your needs, in case you might hook up them all to the CPU fan header using a PWM splitter (albeit depending of your hardware cooling needs).

oneleaf wrote:Generally speaking, is it OK to always buy PWM fans and simply use voltage control when PWM is not available? Or is it important to get the right fan for the right job?
No, it's not ok at all: your second question points to the right move.

oneleaf
Posts: 5
Joined: Thu Aug 23, 2007 8:54 am

Re: Mistakenly bought PWM case fans. Options?

Post by oneleaf » Sat Jul 30, 2016 12:46 pm

Thanks guys,
The Gigabyte board I have (old G33 platform) has very limited BIOS settings for fans. Any type of automatic fan speed setting risked having the fan not spin, so I would have to leave it on full blast. I do plan on getting a new motherboard (Skylake) soon, so I might get one that has PWM chassis fan headers.

Fire-Flare
Posts: 422
Joined: Sun Jun 13, 2010 12:44 pm
Location: Seattle

Re: Mistakenly bought PWM case fans. Options?

Post by Fire-Flare » Sat Jul 30, 2016 4:11 pm

oneleaf wrote:Thanks guys,
The Gigabyte board I have (old G33 platform) has very limited BIOS settings for fans. Any type of automatic fan speed setting risked having the fan not spin, so I would have to leave it on full blast. I do plan on getting a new motherboard (Skylake) soon, so I might get one that has PWM chassis fan headers.
I can vouch for ASUS having excellent fan control; They've integrated custom speed ramping into the BIOS so we don't need to use SpeedFan anymore.

Neocray
Posts: 35
Joined: Mon Mar 14, 2016 2:51 am
Location: France

Re: Mistakenly bought PWM case fans. Options?

Post by Neocray » Wed Aug 03, 2016 9:37 am

Except FanXpert doesn't let you choose which temperature probe is used to set the fan control. That is its only flaw against an aging Speedfan.

Button_Mash
Posts: 26
Joined: Fri Jan 01, 2016 4:39 pm
Location: New Zealand

Re: Mistakenly bought PWM case fans. Options?

Post by Button_Mash » Wed Aug 03, 2016 12:39 pm

Neocray wrote:Except FanXpert doesn't let you choose which temperature probe is used to set the fan control. That is its only flaw against an aging Speedfan.
I can't comment on FanXpert but the ASUS UEFI lets you specify which sensor to use for each fan. The only flaw is that there isn't really a good sensor to use for GPU temperature.

Fire-Flare
Posts: 422
Joined: Sun Jun 13, 2010 12:44 pm
Location: Seattle

Re: Mistakenly bought PWM case fans. Options?

Post by Fire-Flare » Wed Aug 03, 2016 1:27 pm

Button_Mash wrote:
Neocray wrote:Except FanXpert doesn't let you choose which temperature probe is used to set the fan control. That is its only flaw against an aging Speedfan.
I can't comment on FanXpert but the ASUS UEFI lets you specify which sensor to use for each fan. The only flaw is that there isn't really a good sensor to use for GPU temperature.
My Asus Sabertooth Z97 Mark 2 board has headers for temperature probes that I connected to my GPU for custom fan ramping.

Neocray
Posts: 35
Joined: Mon Mar 14, 2016 2:51 am
Location: France

Re: Mistakenly bought PWM case fans. Options?

Post by Neocray » Thu Aug 04, 2016 4:29 am

Well, that is useful. Where did you get the probes ?
Button_Mash wrote:I can't comment on FanXpert but the ASUS UEFI lets you specify which sensor to use for each fan. The only flaw is that there isn't really a good sensor to use for GPU temperature.
I have an Asus UEFI, and it doesn't let me choose the sensor as well.
I have three system-wide monitoring tools: FanXpert (Asus Suite, actually), Speedfan and Corsair Link. Speedfan is not able to control half of the fan headers, FanXpert uses only the CPU temperature sensor, and Corsair Link is the only one to actually show the GPU sensors, but it offers no control over the fans...

Fire-Flare
Posts: 422
Joined: Sun Jun 13, 2010 12:44 pm
Location: Seattle

Re: Mistakenly bought PWM case fans. Options?

Post by Fire-Flare » Thu Aug 04, 2016 1:27 pm

Neocray wrote:Well, that is useful. Where did you get the probes ?
FrozenCPU.com still carries them: http://www.frozencpu.com/products/10767 ... _-_25.html

Abula
Posts: 3662
Joined: Tue Nov 02, 2004 12:22 pm
Location: Guatemala

Re: Mistakenly bought PWM case fans. Options?

Post by Abula » Thu Aug 04, 2016 6:01 pm

Fire-Flare wrote:
Neocray wrote:Well, that is useful. Where did you get the probes ?
FrozenCPU.com still carries them: http://www.frozencpu.com/products/10767 ... _-_25.html
Is frozen operating again? just wondering since it was one of my gotto places for certain things, but last i checked they had some issues. Have you bought from the recently?

Fire-Flare
Posts: 422
Joined: Sun Jun 13, 2010 12:44 pm
Location: Seattle

Re: Mistakenly bought PWM case fans. Options?

Post by Fire-Flare » Thu Aug 04, 2016 8:11 pm

Abula wrote:Is frozen operating again? just wondering since it was one of my gotto places for certain things, but last i checked they had some issues. Have you bought from the recently?
I have not, though my research shows that some of the employees started their own company called ModMyMods, who carry three different lengths of probes:

https://modmymods.com/thermal/cable.html

Post Reply