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Max Fan Speed correct on iMac 17.1?

Control fans on Apple hardware: iMacs, Macbooks, etc

Moderator: Steven

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rossh
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Joined: 03 Feb 2017, 01:40

Max Fan Speed correct on iMac 17.1?

Post by rossh »

Just found this software. Excellent except one small issue. I have an iMac late 2015 27" ie 17.1. It has only one fan with a max speed of 3800rpm. MFC recognises only one fan but only allows a max speed of 2700 rpm. Is there an update planned to correct this? Thanks
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Steven
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Re: Max Fan Speed correct on iMac 17.1?

Post by Steven »

According to our database, this iMac has only 1 fan with max fan speed equal to 2850 RPM. Can you show us a screenshot of Macs Fan Control running?
rossh
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Joined: 03 Feb 2017, 01:40

Re: Max Fan Speed correct on iMac 17.1?

Post by rossh »

Hmm. Thanks for the reply. This is confusing. I have your speed below in screen shot of 2700rpm and 2850 max. A little more research show the Tech Tool Pro Fan Test agrees with these speeds.
However, I had previously used SMC Fan Control but prefer the MFC ability to ramp up speeds automatically. It shows 3,800 rpm as max speed. I can also set speed to 2700rpm which is then confirmed on both SMC FC and iStat Nano and then set to max speed of 3800rpm which is again confirmed by both pieces of software. I can also hear increased fan speed.
So ... a bit of a mystery. Maybe 3800 is possible but not recommended??
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Steven
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Re: Max Fan Speed correct on iMac 17.1?

Post by Steven »

Apple SMC firmware sometimes changes min/max fan speed dynamically, its algorithm is currently unknown.
Macs Fan Control always uses the current settings.
rossh
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Joined: 03 Feb 2017, 01:40

Re: Max Fan Speed correct on iMac 17.1?

Post by rossh »

Thanks for reply. Interesting, as I was using a gaming benchmark today which pushes the GPU and it maxed out about 91 degC. Fan speed went beyond 2700 and in screen shot below you can see I now have a new max speed of 2848rpm. Consistent with your comment above about variable max temperature. Looks like MFC then holds new Max?
Anyway, practically this is fairly academic and MFC is a great piece of software for general use to keep temps down.
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Steven
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Re: Max Fan Speed correct on iMac 17.1?

Post by Steven »

Looks like MFC then holds new Max?
it simply reads max when it starts
rossh
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Joined: 03 Feb 2017, 01:40

Re: Max Fan Speed correct on iMac 17.1?

Post by rossh »

You are right. Next time I started Max Speed returned to 2700 rpm.
rossh
Posts: 5
Joined: 03 Feb 2017, 01:40

Re: Max Fan Speed correct on iMac 17.1?

Post by rossh »

Been looking at this on and off since last correspondence. MFC working very well. However I have noted that the 2014 iMacs had max speed 2700rpm and 2015 iMacs this increased to 2850rpm. Why does my 17.1 iMac (late 2015) still show max 2700rpm? Is a reinstall or something needed? Thanks.
PS: be v.happy to pay for MFC to get extra features eg controlling on either / or CPU or GPU sensors
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Steven
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Re: Max Fan Speed correct on iMac 17.1?

Post by Steven »

There's no need to reinstall the app. The internal mac system sets min/max rpm speed. MFC just uses them.

You can support the app here:
https://www.crystalidea.com/macs-fan-control/buy
gioalf
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Joined: 24 May 2017, 05:21

Re: Max Fan Speed correct on iMac 17.1?

Post by gioalf »

Hi, Macs Fan Control says that my fans can run at 2 different max speed today, but yesterday it was the same, slightly above 6100rpm, now being the right one at 5700 max.

Is the sw preventing the fan from running at max speed?

I need Macs Fan Control so that when I know that the computer will be under full workload it stays cool, fans running at max speed constantly.
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