Explain PWM Pulse Wave Modulation for case fans

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loninappleton
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Joined: Tue Sep 01, 2009 12:19 pm
Location: Wisconsin

Explain PWM Pulse Wave Modulation for case fans

Post by loninappleton » Fri Sep 04, 2015 10:51 am

What is needed at the board or the CPU for PWM?

I understand, maybe erroneously that the speed has to do with heat output.

My boards are old but I continue to upgrade a piece here and there.

These PWM 140 mm fans are reasonably priced now (a Rosewill for $12.00) and I prefer running with fans at slow speeds.

My current fans are all Scythe Kazemaru 140's- a 500 rpm and an 800 rpm.

quest_for_silence
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Location: ITALY

Re: Explain PWM Pulse Wave Modulation for case fans

Post by quest_for_silence » Fri Sep 04, 2015 11:34 am

loninappleton wrote:What is needed at the board or the CPU for PWM?

You need a PWM controller hooked up to the Super I/O chip on the motherboard, with at least a proper 4-pin header wired to it.

CA_Steve
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Re: Explain PWM Pulse Wave Modulation for case fans

Post by CA_Steve » Fri Sep 04, 2015 12:05 pm

Some older mobos support PWM for non-CPU fans, others don't. It's best to list your mobo model for more help.

loninappleton
Posts: 47
Joined: Tue Sep 01, 2009 12:19 pm
Location: Wisconsin

Re: Explain PWM Pulse Wave Modulation for case fans

Post by loninappleton » Fri Sep 04, 2015 12:09 pm

CA_Steve wrote:Some older mobos support PWM for non-CPU fans, others don't. It's best to list your mobo model for more help.
The board in question is a Biostar MCP6PB M2+ for AMD.

Please advise and thanks for your reply.

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

Re: Explain PWM Pulse Wave Modulation for case fans

Post by quest_for_silence » Fri Sep 04, 2015 1:42 pm

loninappleton wrote:The board in question is a Biostar MCP6PB M2+ for AMD.

Please advise and thanks for your reply.

Apparently the case fan header is not suitable, but you could just hook up a "PWM splitter" to the CPU one (which has a nice setup under the PC Health BIOS section).

loninappleton
Posts: 47
Joined: Tue Sep 01, 2009 12:19 pm
Location: Wisconsin

Re: Explain PWM Pulse Wave Modulation for case fans

Post by loninappleton » Fri Sep 04, 2015 4:47 pm

I haven't looked at PC Health much. Will see what's in there.

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