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Resolved How-To: FIX MAC PRO FAN SPEEDS when using PC (non-EFI) Graphics Cards
- Thread starter SteveJobzniak
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In my case (MacPro 4,1 > 5,1, GTX 680 in slot 1, macOS 10.14.5) the mentioned short GPU stressing fixes my high PCI and PSU fan speeds. It's not necessary after sleep/reboot.
I wrote a little AppleScript to be executed at login, similar to friolz'es one.
The only difference is, it checks the current PCI fan speed if GPU stressing is even necessary and it works completely in the background.
It expects "smcFanControl.app" and "Geekbench 5.app" to be present in the Applications folder.
To avoid the opening of a browser window to display the Geekbench results, the connection is blocked with LittleSnitch.
If anyone knows another tool which stresses the GPU "invisible" in the background, I'd like to know.
My method unfortunately needs either a Geekbench or LittleSnitch license.
I wrote a little AppleScript to be executed at login, similar to friolz'es one.
The only difference is, it checks the current PCI fan speed if GPU stressing is even necessary and it works completely in the background.
It expects "smcFanControl.app" and "Geekbench 5.app" to be present in the Applications folder.
To avoid the opening of a browser window to display the Geekbench results, the connection is blocked with LittleSnitch.
If anyone knows another tool which stresses the GPU "invisible" in the background, I'd like to know.
My method unfortunately needs either a Geekbench or LittleSnitch license.
AppleScript:
set MacModel to do shell script "system_profiler SPHardwareDataType | awk '/Model Identifier/ {print $3}'"
if MacModel is "MacPro5,1" then
set PCIFanInfo to do shell script "/Applications/smcFanControl.app/Contents/Resources/smc -k F0Ac -r"
# Output is: F0Ac [fpe2] 799.25 (bytes 0c 7d)
# Extract only RPM (799.25):
set PCIFanSpeed to do shell script "awk 'match($0,/[0-9]{1,4}.[0-9]{1,2}/) {print substr($0,RSTART,RLENGTH)}'<<<" & quoted form of PCIFanInfo
# Round value (799):
set PCIFanSpeed to round of PCIFanSpeed
try
if PCIFanSpeed is greater than 900 then
do shell script "/Applications/Geekbench\\ 5.app/Contents/Resources/geekbench5 --compute OpenCL"
end if
end try
end if
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was there ever a resolution as to why some machines display this differently to others?
If I cold boot my machine, the GPU's fans don't spin up, but the PCI fans ramp up to around 2100 for a minute or so, before falling back down to 600, usually by which time, the gpu's fans have started up.
Under Sierra this was consistent. Under Mojave, it would sometimes seem to get stuck at that higher speed for longer, and the gpu fans wouldn't spin up. I wonder if "better RX580 support" actually translates to "better power management" or rather, "delaying the GPU fans" and the pci fan sticking on is a symptom?
I know if I reboot it when it's been busy the PCI or GPU fan is like a jet engine for ~5 seconds during POST.
If I cold boot my machine, the GPU's fans don't spin up, but the PCI fans ramp up to around 2100 for a minute or so, before falling back down to 600, usually by which time, the gpu's fans have started up.
Under Sierra this was consistent. Under Mojave, it would sometimes seem to get stuck at that higher speed for longer, and the gpu fans wouldn't spin up. I wonder if "better RX580 support" actually translates to "better power management" or rather, "delaying the GPU fans" and the pci fan sticking on is a symptom?
I know if I reboot it when it's been busy the PCI or GPU fan is like a jet engine for ~5 seconds during POST.
It's the SMC that controls fan speeds, not software or drivers, and the SMC firmware has lot's of bugs. One that affects a large part of Mac Pro users is the PCIe fan high RPM during start up.
The common thinking about what is the source of the high PCIe fan speed bug is more or less that the algorithm/matrix that are used to define PCIe fan speeds are based on sampling the power usage of PCIe slots, so if you have a card, not only GPUs, that have a high initial power consumption, the SMC ramps rotation to prevent overheat. This don't work well with aftermarket GPUs and some M.2 switched adapters like HPT SSD7101-A. Usually SMC 1.39f11, after the initialisation of all cards and the subsequent lower power usage from the PCIe slots, takes the PCIe fan rotation to normal levels, but SMC 1.39f5 is problematic and with some Macs the slowdown of the PCIe fan never happens.
Simplifying a lot, newer GPUs like Polaris enter the standard power usage very fast, while some NVIDIA cards like GTX 680 take more than minute to do the same after the driver loads and initialise the GPU. Since most cards have different power usage levels and some people only have one monitor, one card that have high power usage, they never get annoyed by this. People that have a GTX 680 (or old AMD cards with 2+ displays connected) and something like HPT 7101-A, or some other audio hardware that takes long time to enter normal power usage levels, get a long time with high speed PCIe fan, sometimes more than three minutes.
Anyway, since it's a SMC firmware problem, we can't do anything about it.
So in theory, two different 4,1->5,1s with the same hardware should behave the same?
Clearly, there's a difference in the way GPUs (or at least the sapphire pulse rx580) are powered up, between Sierra and Mojave - with the same dual screens, I've watched the card leave its own fans inactive more or less indefinitely at the desktop after boot in Mojave, whereas Sierra always spins them up.
Certainly for me, the "better GPU support" for the RX580 in Mojave looks like a delay in kicking off the GPU's active cooling, leading perhaps to a prolonging of the PCI slot fan's higher RPM - perhaps a conflict between Mojave's GPU driver behaviour (avoid fans unless necessary), and the SMC's (spin fans up until GPU draw / temp does something specific - stabilise, drop, cross some threshold etc).
Last year, I developed AirOut, a small Metal app that resets the system fans by stressing the GPU. When launched as a login item, it automatically checks whether the system fans are spinning too fast, and if so runs a Metal computation. Apart from some notifications, which can be controlled in System Preferences, AirOut is totally invisible.
Because different video cards require different amounts of stress, AirOut will only work for the popular 8 GB RX 580. For other cards, there is a manual forced mode; however, ymmv.
Recently, I’ve been looking into determining a base amount of stress depending on GPU memory, and also allowing users to tweak this amount, opening AirOut to other cards. I plan on making this version available sometime around the release of Catalina.
Wow, yes, that would be exactly what I was looking for.
I will definitely keep track of AirOut.
Thanks for all the info, really learn a lot in this thread. I re-adjust the fan profile in MFC, now the PSU fan still base one the PSU 2nd component, but the temperature range from 33C - 55C.
This make my PSU fan always run above idle, but still below 1000RPM most of the time and virtually no extra fan noise. In fact, when idling, it's just an extra 100RPM, but effectively cool the PSU down for 4C (from 40C to 36C), so it's sounds like a good trade off for potentially longer PSU life (and higher max output)
@h9826790 5 years later, with much more hungry GPUs, do you still use Macs Fan Control? Have your settings evolved? I reinstalled it on a clean Mojave and realised that PSU 2nd Component has changed its name.
I petty much keep the same profile.
And No. I don’t use MFC anymore. It doesn’t fit my needs.
I use a self modified version of the open source Mac Fan Control software. Which allow me to set a higher min RPM, and build a fan profile base on the PSU temperature at the same time. MFC only allow me to do one at a time.
I'm impressed by how much Mac knowledge you've developed over the years. Allows you to really tailor make stuff for your cMP.
Certes Martin Lo (h9826790, username straight out of Blade Runner) is a Macrumors hero @pierrox (in fact I'm using Martin's Powerplay.kext and now his config.plist mod to keep my Radeon VII running reliably on just the built-in PCIe boosters) but Macs Fan Control remains amazing and it's possible to set minimum RPM and have a custom curve for a given fan.
The way to set a minimum RPM is to track a sensor's temperature at idle with minimum fan. Then one sets a fan sensor lowest temperature to one or two degrees below that. That will bring the (noisy) power supply fan up to 700 or 800rpm as minimum RPM. After that adjust maximum temperature for the curve which appeals to you.
I've paid for Macs Fan Control which makes it much more fun to use: as a paid user it's possible to add as many profiles as you like and switch between them, while trying to build the ideal profile. Or for somebody who does have certain activities which require more silence (active music recording) or require more active cooling (rendering), you can have all the custom profiles you like. At €17 I was happy to send Crystal Idea some support for what had been years of free use and for the super powers. It's very cool that Crystal Idea offers a capably free version and has maintained Macs Fan Control for over a decade. I've played around with the copy cats (even own a license for one). While some have a prettier face, none are as reliable and robust as MFC. Where cooling is concerned, there's no room for buggy software.
@foliovision Could you let me know your PCI and PS fan profiles (sensor and min/max temps)? I've installed an RX6600XT recently; AirOut seemed to solve the PCI fan speed issue at first, but since rebooting hasn't been effective. I'm now experimenting with MFC.
Edit: "defaults write com.airoutteam.AirOut StressLevel 110" seems to have fixed it - AirOut just needed to go a little harder.
Edit: "defaults write com.airoutteam.AirOut StressLevel 110" seems to have fixed it - AirOut just needed to go a little harder.
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For PCIe, you may try this value
And PS for this
Depends on your PSU's model number, this may give you a bit high PSU fan noise. In that case, you may adjust the max temperature to fit your own preference.
I'm not running the Mac Pros right now (using an M1 Max) so I'm unable to share my final setup. I was never able to completely quiet down the power supplies, even with a stable of three Mac Pros. The quietest was not bad but under any load, some kind of whine started. The power supply fans were by far the most annoying.
I am not sure if this is applicable in your case.
I've just moved from Hong Kong to Japan. Therefore, the voltage drops from 240V to 110V. And there is no more whine from my cMP's PSU.
What I want is like this, mod the actual min fan speed. So that the fan speed stay at that constant min fan speed most of the time.
If use that "sensor base method", the min fan speed will flucturate base on the room temperature etc. And whenever the fan noise change, it can easily catch my attention. So, that's not ideal for me.
In order to use MFC in the way I want, I will manually set the min fan speed (via smc in terminal) to a level which just won't make noticeable noise. Then use MFC to set the fan profiles base on the sensors.
The closest you can come to this right now is to have multiple profiles (pro version) where you set (some of) your fans on fixed rate depending on the kind of work you are doing. Good idea though. You could ask MFC creators about adding a minimum speed.
Little bit of a necro but this seemed like the most applicable thread. I recently installed a Vega 56 in slot 1 of my cMP4,1>5,1 with the recommended setup of an eVGA PowerLink and using the 150W VBIOS setting on the card. I've got two 4K monitors connected and the card is working fine. Haven't attempted any compute stuff/FCP but in terms of just normal usage it's working great.
I also have a newly-installed HighPoint 7101A with 4 NVMe blades in slot 2.
However, I've noticed that my PCI fan is constantly running about 1450rpm give or take. PSU fan is at ~870rpm. PCIe ambient temp is around 30 (it is still on the cool side in my locale).
I take it this is the "racing fan" bug. I guess I always thought that bug manifested for x minutes after boot and then went away on its own (or one could use one of the methods mentioned in this thread to get rid of it right away). But my fan speeds stay at these higher levels indefinitely.
Maybe it's because I've got both a power-hungry GPU *and* a HighPoint 7101A drawing a lot of power that my SMC wants to keep those two fans at higher speeds?
I don't care about the PSU fan--I don't really hear it below 900rpm, plus given the info in this thread I understand it's important to keep it nice and cool. But the PCI fan at 1400rpm is definitely noticeable and a little bit annoying.
I've successfully used Macs Fan Control to tie it to the PCIe ambient temp as described in the thread, so I can always do that.
But I also wanted to try @cdf's AirOut solution, but haven't had any luck with it. I understand from his last post in the AirOut thread that it won't run properly at login under Monterey, but I am just trying to run it manually and haven't yet seen it decrease my PCI fan speed more than about 20rpm (so like from 1440rpm down to 1420 or so). I have tried setting a stresslevel up to 150 with no change. Should I just keep going with a higher and higher stresslevel? Or is it possible that with the combo of Vega 56+fully-loaded HP7101A that my SMC is seeing high enough voltage draw that it will keep the PCI/PSU fans running faster even after a high-stress exercise of the GPU?
Just wondering if anyone else had a similar experience. Probably most people just use MFC to tie the fans to PCIe ambient and be done with it.
I also have a newly-installed HighPoint 7101A with 4 NVMe blades in slot 2.
However, I've noticed that my PCI fan is constantly running about 1450rpm give or take. PSU fan is at ~870rpm. PCIe ambient temp is around 30 (it is still on the cool side in my locale).
I take it this is the "racing fan" bug. I guess I always thought that bug manifested for x minutes after boot and then went away on its own (or one could use one of the methods mentioned in this thread to get rid of it right away). But my fan speeds stay at these higher levels indefinitely.
Maybe it's because I've got both a power-hungry GPU *and* a HighPoint 7101A drawing a lot of power that my SMC wants to keep those two fans at higher speeds?
I don't care about the PSU fan--I don't really hear it below 900rpm, plus given the info in this thread I understand it's important to keep it nice and cool. But the PCI fan at 1400rpm is definitely noticeable and a little bit annoying.
I've successfully used Macs Fan Control to tie it to the PCIe ambient temp as described in the thread, so I can always do that.
But I also wanted to try @cdf's AirOut solution, but haven't had any luck with it. I understand from his last post in the AirOut thread that it won't run properly at login under Monterey, but I am just trying to run it manually and haven't yet seen it decrease my PCI fan speed more than about 20rpm (so like from 1440rpm down to 1420 or so). I have tried setting a stresslevel up to 150 with no change. Should I just keep going with a higher and higher stresslevel? Or is it possible that with the combo of Vega 56+fully-loaded HP7101A that my SMC is seeing high enough voltage draw that it will keep the PCI/PSU fans running faster even after a high-stress exercise of the GPU?
Just wondering if anyone else had a similar experience. Probably most people just use MFC to tie the fans to PCIe ambient and be done with it.
AFAIK, the native PCIe fan profile base one few parameters, but not just temperatures. PCIe card's power draw (current, not voltage) is one of them. In fact, this make perfect sense. Because whenever the power draw increase, something inside the PCIe compartment will get warmer. So, Apple decided to spin up the fan straight away to keep the cards cool (especially the ancient Apple RAID card is a passive cooling card).
Therefore, your theory is completely possible.
When multiple monitors connected to an AMD graphic card, it's idle power will increase a lot. I am not 100% sure about the Vega, but most like increase from ~15W to ~50W.
If there are multiple NVMe on the 7101A, the typical power draw (not under stress) should be just around 20W.
I am not very sure if ~70W is enough to increase the PCIe fan speed to ~1400RPM. That seems a bit too much for me, but I haven't use the native fan profile for many years already. Really can't quite remember it's behaviour (vs power draw), so your guess is entirely possible.
Anyway, if you haven't try SMC reset yet, you may give it a go.
And you may temporarily disconnect one of the monitor (not just shut it down, but better physically disconnect it), and see if the PCIe fan RPM reduce. If yes, then highly likely your existing high fan speed is due to the PCIe card's power draw.
Good ideas. I will try an SMC reset and also try unplugging one of the DisplayPort cables from the card today and see what effect it has on the PCI fan speeds. Thank you.
Edit: One other question--does hybridization via OC (using board ID of MacPro7,1) affect the fan behavior at all? Or is that 100% determined by the SMC firmware? The reason I ask is because in this thread, the OP found different behavior of the fan on his Vega 64 when spoofing MacPro7,1 vs. spoofing iMacPro1,1. But that is GPU fan--maybe system fans aren't affected?
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AirOut 2 works for me, though my GPU / SSD use less power. I'm running it at login on Monterey. I believe I increased the stress level to 150% before it worked reliably; you could try higher to see if it works for you.
Thanks. Good to know it still works at login on Monterey--maybe @cdf updated it, or perhaps a later point release of Monterey made it work again. I will try some higher stresstest values to see if I can get it to ramp the fans down.
AirOut 2 might not start automatically as a login item in Monterey but should otherwise be functional. AirOut 3 addresses this issue and should be available shortly.
Yeah, different room temperatures and different amounts of power draw (maybe you've got more hungry GPUs and PCI express cards) can account for the rest of the differences. Your temperature ranges for the automatic fan speeds are good. Your temperatures all look great now, and if the fans aren't noisy then congratulations on a job well done! You've extended the life of that Mac by many years!
Each PCI express card can draw up to 75 watts from the slot itself, and the 2x 6-pin connectors for the graphics card both deliver 75 watts each. So having a more loaded machine will draw more power and lead to more heat. So I think that's a likely explanation for most of the temperature differences and your need for higher fan speeds than mine. And ambient temp plays a big role too.
I only have some low-power PCI express cards, and a single graphics card which is one of the most power-efficient ever made (GTX 960, Nvidia's new Maxwell architecture, which uses half the power of their old generations, idles at 9W and tops at 125W at full load, and I almost never load it at all).
And the day our power supplies go "bang" (as all computer power supplies eventually do), remember to look for a friend with electronics repair knowledge, or a local repair shop. It's a pretty simple task to replace capacitors. I've saved thousands of dollars by always doing the home electronics repairs myself instead of buying new power supplies/replacement hardware. But I dream of the day when capacitors are improved beyond "paper+water" technology so that I can stop wasting time with repairs.
This thread has delivered and proven over the past years, to be a golden standard for keeping a Mac Pro 5.1 (mid-2012) cool and collective with no major - except fans by Apple Service - exchange / recap of components in my Mac. Still running as smooth as a Swiss Watch and celebrating its 10-years heavy duty anniversary in March 2024.
The very reliable Mac Fans Control application has proven to be a true life extension for the Mac.
Cheers.
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