MP 1,1-5,1 Fan speed after CPU upgrade?

aaronmacg

macrumors newbie
Original poster
Jun 24, 2019
9
1
Apologies if this is covered elsewhere; I have searched, but haven't found anything definitive.

I recently acquired a single-CPU Mac Pro, which has (for almost its entire life with me) only come with Mojave.

Thanks to the info on these forums, I upgraded it from a W3565 to a X5690 without a seeming hitch. (System boots great, no issues with stress tests, no red lights on the CPU board, etc.) And the resting temperatures are just about the same as the old chip (currently 43ºC HeatSink, 54º Relative to ProcHot, 47ºC Tdiode according to iStats), and all seem within normal parameters I've researched.

However, the operating system just doesn't seem to want to turn on the fans once I upgraded the CPU. I did a Handbrake of a video, and — despite all six cores being maxed out for almost a half hour — the fans didn't come on at all outside of their usual idling levels. (Relative to ProcHot got down to 29ºC and still seemed to be dropping, but Handbrake finished before then.)

I'm all-but-certain that Mojave was spinning up the fans before as I'd expect with the old CPU, because I remember hearing them whir more when I did a similar video compression last week. So I don't think it's related to the operating system per se. (I know that the Mac Pros got stingier with their fan use around Yosemite, IIRC?) I don't recall checking the temperature of my old processor when it was installed, so it's possible that CPU got even hotter than my current chip, and that's why the fans came on before but haven't come on yet with the new chip . . . but I'm honestly not sure.

The fans work fine; in both iStat Menus and Macs Fan Control I can get them to whir however I like.

I've reset both the SMC, PRAM, and NVRAM, to no change.

I know that I can use Macs Fan Control to set a different cooling profile, but I wanted to check first if there was something more or different I needed to do with the CPU upgrade to tell the operating system to start kicking in the fans appropriately, or if there's something subtle going on that I'm not understanding.

Alternatively, if this is just the way it is, if anyone can direct me to recommended settings for Macs Fan Control, I'd be appreciative.

Thanks for everyone's help!
 

h9826790

macrumors G5
Apr 3, 2014
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Hong Kong
Your fans speed are normal.

The fans spin up before you change the CPU may be just because the thermal paste was old, and the cooling efficiency was degraded.

The native fan profile won't spin up the fan until it's around 15°C away from processor hot. If you still have 29°C to go, the fan should stay at idle RPM.
 
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Darmok N Jalad

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Sep 26, 2017
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What does your CPU diode get up to under load? My experience with the cMP is that it really avoids taking fan speeds up above base unless your CPU gets up toward 80C. The massive heatsink is great at pulling the heat away, and there is a large fan inside moving air nicely. I think you'd need relatively high ambient temps to get things spun up.
 

h9826790

macrumors G5
Apr 3, 2014
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What does your CPU diode get up to under load? My experience with the cMP is that it really avoids taking fan speeds up above base unless your CPU gets up toward 80C. The massive heatsink is great at pulling the heat away, and there is a large fan inside moving air nicely. I think you'd need relatively high ambient temps to get things spun up.
If his CPU reach ~29°C ProcHot. The Diode should be around 70°C.
 

donluca

macrumors regular
Jul 30, 2018
183
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Italy
To hell with Apple’s SMC. The thing would wait until my X5690 got to 90°C before start spinning.

I’ll take some fan noise and keep my CPUs under 80°C on full load rather than having a perfectly silent machine and shortening my CPUs (and northbridge) life span.

I just wish Mac Fans control would let us set fan speed according to more than one sensor.
 

Darmok N Jalad

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Sep 26, 2017
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To hell with Apple’s SMC. The thing would wait until my X5690 got to 90°C before start spinning.

I’ll take some fan noise and keep my CPUs under 80°C on full load rather than having a perfectly silent machine and shortening my CPUs (and northbridge) life span.

I just wish Mac Fans control would let us set fan speed according to more than one sensor.
I just use the 3 fans to respond to different sensors. Boost (the one inside the HS) starts to ramp based on CPU Diode, while Intake and Exhaust respond through heatsink temperature. That way a sustained workload kicks off active cooling of the heatsink, and then the other 2 fans will jump in when the Boost fan needs help. I just give the Boost fan a really wide temperature range, that way it slowly ramps up under moderate use.
 

aaronmacg

macrumors newbie
Original poster
Jun 24, 2019
9
1
I've let it chug longer on another Handbrake process. On this process (still ongoing), it's gotten to 73ºC HeatSink, 2ºC Relative to ProcHot, and 86ºC Tdiode. I noticed that Booster 1 finally started whirring up VERY slightly (to 854rpm), as did Exhaust (to 593rpm). All the others stayed flat.

I got nervous and turned the fans onto iStat Menus' Medium settings, which lowered temperatures fine. But I don't know if I'm overthinking it and should trust Apple's engineers, or muck with it (as others have done here) using Macs Fan Control . . . but, if I want to do that, I'm not sure what settings I should be using. (Is there a tutorial or guide somewhere?)
 

Darmok N Jalad

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Sep 26, 2017
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MacsFanControl is a great solution, and one with a fair amount of control. Personally, I don't like that much heat, but considering that we are all using machines almost 10 years old, it's hard to say that the way they are designed to operate has really shortened their lifespans!
 

donluca

macrumors regular
Jul 30, 2018
183
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Italy
I've let it chug longer on another Handbrake process. On this process (still ongoing), it's gotten to 73ºC HeatSink, 2ºC Relative to ProcHot, and 86ºC Tdiode. I noticed that Booster 1 finally started whirring up VERY slightly (to 854rpm), as did Exhaust (to 593rpm). All the others stayed flat.

I got nervous and turned the fans onto iStat Menus' Medium settings, which lowered temperatures fine. But I don't know if I'm overthinking it and should trust Apple's engineers, or muck with it (as others have done here) using Macs Fan Control . . . but, if I want to do that, I'm not sure what settings I should be using. (Is there a tutorial or guide somewhere?)
The whole thing revolves around the X-tier Xeons being able to work up to 125°C before going into thermal throttling, so Apple’s SMC won’t start making the fans spinning until the CPU goes up to 86°C (I believe that’s the ProcHot point) and then increase to keep them below thermal throttling.
And that’s without taking into consideration how hot the RAM modules and the northbridge become: it quickly becomes a damn oven in there without doing much.

I really don’t like the idea of having them being so warm for no good reason. By making the fans go slightly faster (1200rpm boosts and 900rpm exhaust and intake) I can keep the CPUs below 50°C easily, the Northbridge below 60°C and RAM modules happily below 45°C.
Those are fine temps for just doing your daily browsing, listening to music and watching videos, plus various office work.
And the system is, if not completely silent, well below the background noise.

Really, there’s absolutely no reason to let your components get so hot, Macs Fan Control is the way to go.
 

h9826790

macrumors G5
Apr 3, 2014
12,784
5,595
Hong Kong
I've let it chug longer on another Handbrake process. On this process (still ongoing), it's gotten to 73ºC HeatSink, 2ºC Relative to ProcHot, and 86ºC Tdiode. I noticed that Booster 1 finally started whirring up VERY slightly (to 854rpm), as did Exhaust (to 593rpm). All the others stayed flat.

I got nervous and turned the fans onto iStat Menus' Medium settings, which lowered temperatures fine. But I don't know if I'm overthinking it and should trust Apple's engineers, or muck with it (as others have done here) using Macs Fan Control . . . but, if I want to do that, I'm not sure what settings I should be using. (Is there a tutorial or guide somewhere?)
As long as the thermal paste and the cooling system is in good condition. That
The whole thing revolves around the X-tier Xeons being able to work up to 125°C before going into thermal throttling, so Apple’s SMC won’t start making the fans spinning until the CPU goes up to 86°C (I believe that’s the ProcHot point) and then increase to keep them below thermal throttling.
And that’s without taking into consideration how hot the RAM modules and the northbridge become: it quickly becomes a damn oven in there without doing much.

I really don’t like the idea of having them being so warm for no good reason. By making the fans go slightly faster (1200rpm boosts and 900rpm exhaust and intake) I can keep the CPUs below 50°C easily, the Northbridge below 60°C and RAM modules happily below 45°C.
Those are fine temps for just doing your daily browsing, listening to music and watching videos, plus various office work.
And the system is, if not completely silent, well below the background noise.

Really, there’s absolutely no reason to let your components get so hot, Macs Fan Control is the way to go.
From memory, according to the Intel processor diagnostics tool, the Mac diode temperature for X56xx should be 105C, not 125C.

And thermal throttling will occurs before that.

The native SMC fan profile should able to keep the CPU just below thermal throttling point. However, if the thermal paste dried up, or the heatsink is a bit dusty etc. Some momentary temperature fluctuations may lowering (or even disable) turbo boost.

And the max turbo boost won’t comeback back again until the cpu cool down again quite a bit.
 

donluca

macrumors regular
Jul 30, 2018
183
90
Italy
I’m 99% sure that 105°C is for the lower grade Xeons (E and W). The X reach up to 125°C.