MacOS trminal help

[OrdinaryPhil]

I'm looking for some help trying to optimize a 27" iMac I was given.

I don't really use Macs all that often, and I am beginning to remember why as I try and integrate this into my home office.

All I am really using the iMac for presently is youtube and some basic web browsing. I do all my browsing in Safari/Firefox on this device and in both cases, the device gets REALLY hot, and REALLY loud. I downloaded the Intel Power Gadget and the system is basically always running at its turbo frequency under any use at all. If I close all my apps, it slowly cools down and the fan speed reduces to a tolerable level, but the moment I even open a browser, it kicks back into Turbo Boost and starts spinning up the fan.

I loathe downloading apps that I don't have to (I have very well founded trust issues), and more or less all my attempts to search for ways to disable Turbo Boost in MacOS have return the same result; download Turbo Boost Switcher.

There has to be another way.

Can anyone assist me with this? Gotta get the fan noise and temps under control.

[Donut417]

30 minutes ago, OrdinaryPhil said:

I'm looking for some help trying to optimize a 27" iMac I was given.

I don't really use Macs all that often, and I am beginning to remember why as I try and integrate this into my home office.

All I am really using the iMac for presently is youtube and some basic web browsing. I do all my browsing in Safari/Firefox on this device and in both cases, the device gets REALLY hot, and REALLY loud. I downloaded the Intel Power Gadget and the system is basically always running at its turbo frequency under any use at all. If I close all my apps, it slowly cools down and the fan speed reduces to a tolerable level, but the moment I even open a browser, it kicks back into Turbo Boost and starts spinning up the fan.

I loathe downloading apps that I don't have to (I have very well founded trust issues), and more or less all my attempts to search for ways to disable Turbo Boost in MacOS have return the same result; download Turbo Boost Switcher.

There has to be another way.

Can anyone assist me with this? Gotta get the fan noise and temps under control.

Did you try spraying out the vents with compressed air? I only ask because thats about what you can do. Macs run hot. Thats one of the many reason Apple decided to switch from Intel. My guess however, is that its just dusty. I have a MacBook Pro and while the fans ramp up when I play a few games or have a lot running. Generally web browsing its not an issue. 

[BondiBlue]

What iMac is this? My absolute furnace of a Mid 2011 27" iMac never gets loud under load, and it doesn't slow down either. 

[OrdinaryPhil]

15 minutes ago, BondiBlue said:

What iMac is this? My absolute furnace of a Mid 2011 27" iMac never gets loud under load, and it doesn't slow down either. 

iMac 18.3

Mid 2017 iMac 5k.
It's an i5 CPU with 64GB RAM.
Has a VERY loud mechanical HDD as well

 

[OrdinaryPhil]

19 minutes ago, Donut417 said:

Did you try spraying out the vents with compressed air? I only ask because thats about what you can do. Macs run hot. Thats one of the many reason Apple decided to switch from Intel. My guess however, is that its just dusty. I have a MacBook Pro and while the fans ramp up when I play a few games or have a lot running. Generally web browsing its not an issue. 

I've cleaned it as thoroughly as it can be cleaned from the exterior. I blew in some air with a compressor but it made no difference. Either very little dust was present or I just blew it further into the chassis where is can't be cleaned >.<

[BondiBlue]

8 minutes ago, OrdinaryPhil said:

iMac 18.3

Mid 2017 iMac 5k.
It's an i5 CPU with 64GB RAM.
Has a VERY loud mechanical HDD as well

That's odd. It shouldn't get loud when just using a browser. Have you tried a fresh installation of macOS?

Also, the hard drive shouldn't be very audible at all, so it could be failing. 

[OrdinaryPhil]

Well, to be fair, I am spoiled and am accustomed to SSDs, where there is no motor, no seek-arm, and no spinning platters. So any HDD is going to be loud by comparison. Having said that, I don't mean that the drive is louder than normal - as I said, all HDDs are loud when they seek. What I do mean is that Apple has a nonsensical arrangement of high-end and low-end parts. There is a 28GB NVMe (presumably 32GB before formatting) drive for the OS - which is no enough IMO, and a 1TB traditional HDD that together Apple refers to as a Hybrid Drive. To be clear - it's not a single 3.5" HDD with a large 32GB Cache like most "hybrid" HDDs... this is a very small NVMe SSD using Apple's proprietary NVMe header, and a bog-standard 1TB HDD from Seagate with some Apple-specific firmware and a fancy sticker. Because the 28GB SSD is so small, nearly anything you in MacOS from watching a YouTube video to posting a forum end up be logged and cached to the HDD, causing near-constant read/writes that result in heat and noise.

I've ordered a toolkit for opening the device up (that little pizza-cutter looking thingamajigger) and I will see if removing the HDD results in a usable system on 28GB, or if I'll need to toss in an SSD as a replacement. Either way, it's just one piece of the noise-puzzle and I don't think that the HDD is the sole reason why the fans are so loud... and constantly on.

The CPU should have an base frequency of 3.4GHz, and a turbo of 3.8GHz... shaving off 400MHz from 4 cores should reduce the heat by a significant amount, and hopefully reduce fan speed/noise. I just need to know how to do that. It's a shame Apple doesn't have an accessible UEFI pre-boot environment for features such as this.

[BondiBlue]

7 hours ago, OrdinaryPhil said:

Well, to be fair, I am spoiled and am accustomed to SSDs, where there is no motor, no seek-arm, and no spinning platters. So any HDD is going to be loud by comparison. Having said that, I don't mean that the drive is louder than normal - as I said, all HDDs are loud when they seek. What I do mean is that Apple has a nonsensical arrangement of high-end and low-end parts. There is a 28GB NVMe (presumably 32GB before formatting) drive for the OS - which is no enough IMO, and a 1TB traditional HDD that together Apple refers to as a Hybrid Drive. To be clear - it's not a single 3.5" HDD with a large 32GB Cache like most "hybrid" HDDs... this is a very small NVMe SSD using Apple's proprietary NVMe header, and a bog-standard 1TB HDD from Seagate with some Apple-specific firmware and a fancy sticker. Because the 28GB SSD is so small, nearly anything you in MacOS from watching a YouTube video to posting a forum end up be logged and cached to the HDD, causing near-constant read/writes that result in heat and noise.

I've ordered a toolkit for opening the device up (that little pizza-cutter looking thingamajigger) and I will see if removing the HDD results in a usable system on 28GB, or if I'll need to toss in an SSD as a replacement. Either way, it's just one piece of the noise-puzzle and I don't think that the HDD is the sole reason why the fans are so loud... and constantly on.

The CPU should have an base frequency of 3.4GHz, and a turbo of 3.8GHz... shaving off 400MHz from 4 cores should reduce the heat by a significant amount, and hopefully reduce fan speed/noise. I just need to know how to do that. It's a shame Apple doesn't have an accessible UEFI pre-boot environment for features such as this.

It's a Fusion Drive. They aren't known to be fast. I'd just replace the entire thing with an SSD if I were you. Still, you shouldn't be able to hear the mechanical drive. It's only a 2.5" drive, and unless it's got a problem it should be pretty quiet. 

[OrdinaryPhil]

On 4/12/2021 at 7:09 PM, Donut417 said:

Did you try spraying out the vents with compressed air? I only ask because thats about what you can do. Macs run hot. Thats one of the many reason Apple decided to switch from Intel. My guess however, is that its just dusty. I have a MacBook Pro and while the fans ramp up when I play a few games or have a lot running. Generally web browsing its not an issue. 

 

Apple switched from Intel because Apple is one of the few companies with enough economic leverage to cut a chip-maker out of their product stack. If you swapped the Intel CPUs with AMD CPUs the iMacs would run just as hot - a single fan is not enough to keep the system cool and remain quiet.

It still doesn't really help me though - obvious there is some method from within the OS to control CPU timing, or apps like Turbo Switcher wouldn't exist. I was hoping that someone here could point me the right direction to maybe run a script or use the Terminal or menually disable Turbo Boost, but seems like I'll need to continue the search

[Donut417]

22 minutes ago, OrdinaryPhil said:

I was hoping that someone here could point me the right direction to maybe run a script or use the Terminal or menually disable Turbo Boost, but seems like I'll need to continue the search

MacOS is pretty closed. Thats how Apple's ecosystem is. If there is a 3rd party app that does what you seek, you most likely will have to use that app. 

 

23 minutes ago, OrdinaryPhil said:

If you swapped the Intel CPUs with AMD CPUs the iMacs would run just as hot - a single fan is not enough to keep the system cool and remain quiet.

I never said that they wouldn't run hot with AMD CPU's. But that is WHY Apple switched. Because the only way to make these devices more thin and pretty is to use ARM. Plus Apple was never going to give AMD a chance because frankly we had a decade of AMD having its head up its ass. Apple was not going to jump to AMD and just have the same shit happen as what's happening with Intel currently. 

 

Once you pop open the machine you should be able to clean it better. If you're brave you might change the thermal compound to something better. 

[OrdinaryPhil]

10 minutes ago, Donut417 said:

MacOS is pretty closed. Thats how Apple's ecosystem is. If there is a 3rd party app that does what you seek, you most likely will have to use that app. 

 

I never said that they wouldn't run hot with AMD CPU's. But that is WHY Apple switched. Because the only way to make these devices more thin and pretty is to use ARM. Plus Apple was never going to give AMD a chance because frankly we had a decade of AMD having its head up its ass. Apple was not going to jump to AMD and just have the same shit happen as what's happening with Intel currently. 

 

Once you pop open the machine you should be able to clean it better. If you're brave you might change the thermal compound to something better. 

I mostly agree about the Intel / AMD situation. I'm not a 'fanboy' of either company, or Apple for that matter - all of them rely on slave labor in SE Asia for their product fabrication and I don't like that - Intel moving their fab to the US is a huge gain. Knowing that people won't be leaping out of buildings to provide me with a CPU isa win for humanity so... I'll be glad to see that become a reality.

Back on topic though; I will probably do a pretty cleaning of the iMac when the opening kit arrives. I've done this a few times to the older 2012ish 27" iMacs, but they weren't glued shut so...

I am just not very optimistic that the system will be any quieter after. The only system fan is a crappy blower that is not very quiet to begin with, and it's basically always on.

If I disable Turbo, the CPU should run 10-15c cooler, but the fan will still be on . Replacing the HDD with a 2.5" SSD will also help, but again, the system still won't be capable of running without the fan. I have plenty of spare 2.5" SATA SSDs, but I wonder if it may not be better to just remove the second drive completely and just invest in a higher capacity NVMe/apple drive.

IF there is no way to disable turbo -is there a method for manually adjusting the system fan speed?

[Donut417]

3 minutes ago, OrdinaryPhil said:

IF there is no way to disable turbo -is there a method for manually adjusting the system fan speed?

So here's the thing. I have the latest model Intel Based MacBook Pro. But the fan really only kicks on when Im doing some light gaming. Web browsing and such it rarely kicks on. Mind you its driving a 1440p ultrawide and a 1080p Ultrawide monitor as well. I would guess that it has the same or similar crappy blower style fan. I haven't used any software and I just checked an there is one app that was $9.99 that said something about monitor temps but Im not sure if it will control your fans. I found a utility called SensorX thats $2.99, but reviews are kinda meh. It really comes down to how much money you want to attempt to throw at the problem. 

 

Personally if I managed to open that machine, Id try to replace the thermal compound with something better and just give the fan a really really really good cleaning and see what happens. Ive seen new thermal compound work miracles. Maybe try starting the machine while its open to see if the fan is working correctly. Another idea is to maybe buy a small table top fan and point it at the machine. 

[OrdinaryPhil]

7 minutes ago, Donut417 said:

So here's the thing. I have the latest model Intel Based MacBook Pro. But the fan really only kicks on when Im doing some light gaming. Web browsing and such it rarely kicks on. Mind you its driving a 1440p ultrawide and a 1080p Ultrawide monitor as well. I would guess that it has the same or similar crappy blower style fan. I haven't used any software and I just checked an there is one app that was $9.99 that said something about monitor temps but Im not sure if it will control your fans. I found a utility called SensorX thats $2.99, but reviews are kinda meh. It really comes down to how much money you want to attempt to throw at the problem. 

 

Personally if I managed to open that machine, Id try to replace the thermal compound with something better and just give the fan a really really really good cleaning and see what happens. Ive seen new thermal compound work miracles. Maybe try starting the machine while its open to see if the fan is working correctly. Another idea is to maybe buy a small table top fan and point it at the machine. 

Well, IMO most apple device are glorified extras attached to really nice displays. I hate MacOS. I hate the proprietary parts. And I honestly don't care for the design. Their displays are some of, if not the best on the market. However, they get hot. LEDs are not magic, and they generate a lot of heat.

With that out of the way - Apple isn't all bad. When your only 3 options are Linux, MacOS, and Windows - MacOS is technically the most respectful of your privacy. But the Apps aren't. I have no problem at all paying a few bucks for an app - I just don't trust them.

[Donut417]

14 minutes ago, OrdinaryPhil said:

Well, IMO most apple device are glorified extras attached to really nice displays. I hate MacOS. I hate the proprietary parts. And I honestly don't care for the design. Their displays are some of, if not the best on the market. However, they get hot. LEDs are not magic, and they generate a lot of heat.

With that out of the way - Apple isn't all bad. When your only 3 options are Linux, MacOS, and Windows - MacOS is technically the most respectful of your privacy. But the Apps aren't. I have no problem at all paying a few bucks for an app - I just don't trust them.

Have you considered selling the machine? I mean even older Macs are worth money. Especially if your not happy with it. 

[OrdinaryPhil]

1 minute ago, Donut417 said:

Have you considered selling the machine? I mean even older Macs are worth money. Especially if your not happy with it. 

Not really. Selling something that was gifted to you isn't very respectful IMO. And I don't mean to imply that I am unhappy with it. Like anything I own, I want it to be the best that it can be. I genuinely mean that. Even if it's not the device I would have purchased for myself, it does have a great 5k display and would make an excellent media consumption device in my office for watching YouTube and listening to music. My goal isn't to just gripe about it. I want to fix it; get it running efficiently enough that the fan isn't always running the HDD isn't spinning all the time. While it is funny that the loudest, hottest, and least efficient PC in my home is a $2,000+ iMac, it's still something I want to get working right.