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+12V vs Speed Control vs VCC

duo1

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+12V vs Speed Control vs VCC
« on: September 02, 2016, 12:57:31 pm »
What's the difference between:

1. +12V (CPU FUN - 2 pin) and Speed Control (SYS Fun 1, 3 - 2 pin)

2. Speed Control (CPU FUN, SYS FUN 2 - 4 pin) and VCC (SYS FUN 1, 2 - 4 pin)

shadowsports

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Re: +12V vs Speed Control vs VCC
« Reply #1 on: September 02, 2016, 03:06:25 pm »
Can you tell us which product you are referencing please?

The number of pins a header has can determine what features/control it supports.  Always on vs. variable speed, speed reporting. 
« Last Edit: September 02, 2016, 03:12:38 pm by shadowsports »
Z390 AORUS PRO (F10) \850w, 9900K, 32GB GSkill TriZ RGB - 16-18-18-38, RTX 3080Ti FTW3 Ultra, 960 Pro_m.2, W11
Z370-HD3P (F5) \750w, 8350K, 8GB LPX 3200 - 16-18-18-38, GTX 970 FTW SC, Intel SSD, 2TB RAID1, W11
Z97X-UD5H \850w, 4790K, 32GB Vengeance, RTX 2080 FTW

duo1

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Re: +12V vs Speed Control vs VCC
« Reply #2 on: September 02, 2016, 03:53:57 pm »
GA-Z170X-Designare

I do not mean the number of pins but with a difference
« Last Edit: September 02, 2016, 03:55:15 pm by duo1 »

shadowsports

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Re: +12V vs Speed Control vs VCC
« Reply #3 on: September 03, 2016, 06:38:52 am »
GA-Z170X-Designare

I do not mean the number of pins but with a difference


Is this a question or a statement?  What is your question? 
« Last Edit: September 03, 2016, 06:39:34 am by shadowsports »
Z390 AORUS PRO (F10) \850w, 9900K, 32GB GSkill TriZ RGB - 16-18-18-38, RTX 3080Ti FTW3 Ultra, 960 Pro_m.2, W11
Z370-HD3P (F5) \750w, 8350K, 8GB LPX 3200 - 16-18-18-38, GTX 970 FTW SC, Intel SSD, 2TB RAID1, W11
Z97X-UD5H \850w, 4790K, 32GB Vengeance, RTX 2080 FTW

duo1

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Re: +12V vs Speed Control vs VCC
« Reply #4 on: September 03, 2016, 10:15:01 am »
What's the difference between:

1. +12V (CPU FUN - 2 pin) and Speed Control (SYS Fun 1, 3 - 2 pin)

2. Speed Control (CPU FUN, SYS FUN 2 - 4 pin) and VCC (SYS FUN 1, 2 - 4 pin)


shadowsports

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Re: +12V vs Speed Control vs VCC
« Reply #5 on: September 03, 2016, 03:24:10 pm »
What's the difference between:

1. +12V (CPU FUN - 2 pin) and Speed Control (SYS Fun 1, 3 - 2 pin)

2. Speed Control (CPU FUN, SYS FUN 2 - 4 pin) and VCC (SYS FUN 1, 2 - 4 pin)





There are about 5 variants of the GA-Z170X-XXX - I'll just pick one.

GA-170X-UD5

Based on my understanding of this.

1.  If you use a 2 pin FAN on a 3-4 pin header, the fan will run at full speed since it is receiving constant 12v.  Speed control is not possible.

2. PWM vs. VCC - 12v vs. 5v..  Poor non standard implementation.  MB manufacturers have not done a good job agreeing on a standard for FAN control.  Some headers use Pulse Width Modulation, while others use VCC.  Some say its called variable voltage, some refer to it as collector control.  The theory is you are suppose to be able to use splitters on the SYS_FAN 1/2/3 headers but not on the CPU_FAN header as the latter only has the ability to control the speed of one fan.

I'm using 3 PIN fans on my SYS_FAN headers without problems.  All run at variable RPM depending on heat/load.
Z390 AORUS PRO (F10) \850w, 9900K, 32GB GSkill TriZ RGB - 16-18-18-38, RTX 3080Ti FTW3 Ultra, 960 Pro_m.2, W11
Z370-HD3P (F5) \750w, 8350K, 8GB LPX 3200 - 16-18-18-38, GTX 970 FTW SC, Intel SSD, 2TB RAID1, W11
Z97X-UD5H \850w, 4790K, 32GB Vengeance, RTX 2080 FTW

duo1

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Re: +12V vs Speed Control vs VCC
« Reply #6 on: September 03, 2016, 05:09:58 pm »
Thx.