Explain PWM Pulse Wave Modulation for case fans

[loninappleton]

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]

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]

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

[loninappleton]

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]

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]

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