iMac 2019 runs occasionally at 100°C? [Merged]

[ferencav]

With my former iMac I never bothered looking at things like temperatures and fan speeds. They said it just works, and it always did. But now in 2019 with all the stories about thermal throttling I wanted to see for myself if my new i9 iMac runs as smoothly as everyone says.

I installed TG Pro and Intel Power Gadget and started a render in After Effects. It's going very fast, but it also gets really hot. At least I think.

After a minute TG Pro reads 100° Celsius occasionally with an average around 95°. The temperature in Intel Power Gadget never gets higher than 95° and gives an average around 92°. Since this software if from Intel, maybe it gets more precise readings?

I'm not that familiar with core temperatures, so I would like to know if these results are ok. I would like to use my iMac for at least 6 years just like my last one

 

[flyinmac]

Generally speaking, if you have not modified your computer. And if you are not deliberately over clocking or manipulating the performance characteristics of your computer. It should operate just fine as it came out of the box.

The computer has built-in mechanisms to prevent operating in an overtemp state. It will automatically reduce performance if it gets too hot. And it will shut down if it’s unable to reduce its temperature in an extreme overtemp condition.

So I see no reason that there should be any issues if you just use it.

Of course, that doesn’t mean you’ll necessarily get the maximum performance that the CPU is capable of at all times. But I would not expect it to die because you are doing intense work on it.

Of course, there are times when parts do fail. But assuming that you have no defective parts, I wouldn’t worry about just using the computer as it is.

 

[wardie]

Did you notice much drop in clock frequency when the temps were max’ing out? On the “old” i7 I’ve found that I can’t sustain turbo boost speeds (4.5GHz) running CPU intensive jobs as you get thermal throttling cycles plus max fan noise, but by switching turbo boost off (4.2GHz) it runs fine with a medium speed fan and slightly lower temps at a sustained pace. Be interesting to see if the i9 can do better as there is a bigger turbo boost effect on this chip (3.6->5.0).

 

[WrightBrain]

With my former iMac I never bothered looking at things like temperatures and fan speeds. They said it just works, and it always did. But now in 2019 with all the stories about thermal throttling I wanted to see for myself if my new i9 iMac runs as smoothly as everyone says.

I installed TG Pro and Intel Power Gadget and started a render in After Effects. It's going very fast, but it also gets really hot. At least I think.

After a minute TG Pro reads 100° Celsius occasionally with an average around 95°. The temperature in Intel Power Gadget never gets higher than 95° and gives an average around 92°. Since this software if from Intel, maybe it gets more precise readings?

I'm not that familiar with core temperatures, so I would like to know if these results are ok. I would like to use my iMac for at least 6 years just like my last one

I've heard many Mac users say 95 - 100 degrees is no big deal. But, professional PC builders say you really don't want temps to go over 80. This is not with overclocking, this is with stock speeds. Now the chip itself may not fail but the other components in the machine could potentially get damaged over time. Not to mention if the fans have to work harder, dust could build up and there's no way to clean out an iMac.

Do me a favor if you could. Could you do the same test but with Turbo Boost turned off? You can download a free app to toggle it on and off. It's call Turbo Boost Switcher. If not no worries. Supposedly it will lower the temp by 20 degrees, but you will probably see degraded performance. I've heard people say in real world application it doesn't really make things noticeably slower.

http://tbswitcher.rugarciap.com/

 

[mdnz]

I've heard many Mac users say 95 - 100 degrees is no big deal. But, professional PC builders say you really don't want temps to go over 80. This is not with overclocking, this is with stock speeds. Now the chip itself may not fail but the other components in the machine could potentially get damaged over time. Not to mention if the fans have to work harder, dust could build up and there's no way to clean out an iMac.

A properly cooled PC has a hard time reaching over 50c even. I'm running a 6700k and even with 100% cpu usage it rarely gets above 50c. Here's my Hackintosh running at 100% cpu for a bit and it doesn't even touch 50. The iMac's cooling is just that bad.

To the OP: It most likely won't matter but keep in mind the things WrightBrain said, they're definitely true.

 

[WrightBrain]

A properly cooled PC has a hard time reaching over 50c even. I'm running a 6700k and even with 100% cpu usage it rarely gets above 50c. Here's my Hackintosh running at 100% cpu for a bit and it doesn't even touch 50. The iMac's cooling is just that bad.

When I've seen people discuss 80 degree temps in PC's it's usually about the new i9 9900K and i7 9700K, which are both bears to cool. I'm contemplating a build using the 9700K and an Noctura NH-d15 cpu fan. But I'm concerned THAT won't be enough and I really didn't want to go liquid.

I should add that that Apple alone isn't at fault for the high CPU temps. Intel has been making high-powered chips with either bad paste and now insufficient solder. The chips are hot in the first place and then Apple tried to cram them into old cases that really were only optimized for 65w chips and under.

 

[mavericks7913]

I've heard many Mac users say 95 - 100 degrees is no big deal. But, professional PC builders say you really don't want temps to go over 80. This is not with overclocking, this is with stock speeds. Now the chip itself may not fail but the other components in the machine could potentially get damaged over time. Not to mention if the fans have to work harder, dust could build up and there's no way to clean out an iMac.

Do me a favor if you could. Could you do the same test but with Turbo Boost turned off? You can download a free app to toggle it on and off. It's call Turbo Boost Switcher. If not no worries. Supposedly it will lower the temp by 20 degrees, but you will probably see degraded performance. I've heard people say in real world application it doesn't really make things noticeably slower.

http://tbswitcher.rugarciap.com/

I guess Mac users are not aware of the temperature at all. Below 70C is quite normal except for 9th gen Intel CPU.

But we also need to blame Apple for having a poor cooling system. This is not the first time having to overheat and throttle. iMac is well known for having throttle due to the poor cooling system.

Mac Pro 2013 is a great example. There is only one fan to cool 1 CPU and 2 GPU at once. I used it for 4 years and I always had thermal throttling. As a result, GPU failed several times and Apple had to admit their failure. Mac Mini also has a similar issue.

It is very obvious anyway. Mac computers are not able to use both high-end air cooler and water cooler, only one fan to cool both GPU and CPU, stupid and poor overall design, and no way to open Mac computers for cleaning.

 

[ferencav]

Generally speaking, if you have not modified your computer. And if you are not deliberately over clocking or manipulating the performance characteristics of your computer. It should operate just fine as it came out of the box.

The computer has built-in mechanisms to prevent operating in an overtemp state. It will automatically reduce performance if it gets too hot. And it will shut down if it’s unable to reduce its temperature in an extreme overtemp condition.

So I see no reason that there should be any issues if you just use it.

Of course, that doesn’t mean you’ll necessarily get the maximum performance that the CPU is capable of at all times. But I would not expect it to die because you are doing intense work on it.

Of course, there are times when parts do fail. But assuming that you have no defective parts, I wouldn’t worry about just using the computer as it is.

Thanks that's exactly what I needed to know. If these temperatures are hot, but within limits I am completely happy with it. At this moment I'm only running some lightweight programs and it's running at 33º Celsius.

Did you notice much drop in clock frequency when the temps were max’ing out? On the “old” i7 I’ve found that I can’t sustain turbo boost speeds (4.5GHz) running CPU intensive jobs as you get thermal throttling cycles plus max fan noise, but by switching turbo boost off (4.2GHz) it runs fine with a medium speed fan and slightly lower temps at a sustained pace. Be interesting to see if the i9 can do better as there is a bigger turbo boost effect on this chip (3.6->5.0).

I ran multiple heavy 8K renders of approximately 30 minutes in After Effects and it ran around 4.6 Ghz the whole time. So I am very impressed by this. Also because Max Tech tested it and it was running just above the base clock (3.6Ghz).
[doublepost=1555157034][/doublepost]

I've heard many Mac users say 95 - 100 degrees is no big deal. But, professional PC builders say you really don't want temps to go over 80. This is not with overclocking, this is with stock speeds. Now the chip itself may not fail but the other components in the machine could potentially get damaged over time. Not to mention if the fans have to work harder, dust could build up and there's no way to clean out an iMac.

Do me a favor if you could. Could you do the same test but with Turbo Boost turned off? You can download a free app to toggle it on and off. It's call Turbo Boost Switcher. If not no worries. Supposedly it will lower the temp by 20 degrees, but you will probably see degraded performance. I've heard people say in real world application it doesn't really make things noticeably slower.

http://tbswitcher.rugarciap.com/

Thanks for the Turbo Switch tip. Maybe I wil test this in the near future. Although everything says this software and author are completely legit, I'm just a bit reserved using this kind of software. When reading the comment section many people are indeed getting a 20 degrees lower temperature.
[doublepost=1555157855][/doublepost]

I guess Mac users are not aware of the temperature at all. Below 70C is quite normal except for 9th gen Intel CPU.

But we also need to blame Apple for having a poor cooling system. This is not the first time having to overheat and throttle. iMac is well known for having throttle due to the poor cooling system.

Mac Pro 2013 is a great example. There is only one fan to cool 1 CPU and 2 GPU at once. I used it for 4 years and I always had thermal throttling. As a result, GPU failed several times and Apple had to admit their failure. Mac Mini also has a similar issue.

It is very obvious anyway. Mac computers are not able to use both high-end air cooler and water cooler, only one fan to cool both GPU and CPU, stupid and poor overall design, and no way to open Mac computers for cleaning.

My iMac 2019 runs steady on 4.6Ghz on heavy load which is 1 Ghz higher than the base clockspeed. So thermal throttling is no issue on this machine. It is unfortunate you can't clean your iMac yourself, although I never had to with my previous one. And if so, there are lots of places (official and unofficial) which offer a dust cleaning service.

 

[Bohemien]

At this moment I'm only running some lightweight programs and it's running at 33º Celsius. I ran multiple heavy 8K renders of approximately 30 minutes in After Effects and it ran around 4.6 Ghz the whole time. So I am very impressed by this. Also because Max Tech tested it and it was running just above the base clock (3.6Ghz).

That sounds very promising! Do you have the 580X or Vega GPU? How bad was fan noise during that 30min rendering? Did you hear the fans all the time?

Thanks!

 

[ferencav]

I have the Vega 48 GPU. However After Effects relies completely on the CPU when rendering.

During a render the fan noise is quite loud when I compare it to my previous iMac (late 2012). It ramps up from 1200 to 2000 rpm so it's definitely present. The 2012 iMac was completely silent and almost never ramped up. Even during heavy rendering. But this is what you would expect if you insert all this new computing power in the same chassis.

The new iMac is also a bit louder when idling. Although this is only a difference of 5db, it's the difference between silent and audible for me.

Personally it doesn't matter to me if it ramps up during a render. Most of the time it's on the end of my working day and I'm leaving my desk. However I'm a bit disappointed by the sound when idling. Although it's very silent it sounds as if the fan could use a drop of oil.

 

[Bohemien]

The new iMac is also a bit louder when idling. Although this is only a difference of 5db, it's the difference between silent and audible for me. Although it's very silent it sounds as if the fan could use a drop of oil.

Yes, that's one unknown variable for me. I refrained from buying the 2017 iMac because I read about the heat/noise issues and am enjoying my nearly completely silent MBP. Apparently this low fan noise is also present in the 2019 iMacs with the 65W TDP CPUs, so there's no escaping it. I'll see when I get it how much it bothers me, I hope I can get used to it (after all, we've been using computers with fans like vacuum cleaners for a long time... ).

 

[ferencav]

Yes, that's one unknown variable for me. I refrained from buying the 2017 iMac because I read about the heat/noise issues and am enjoying my nearly completely silent MBP. Apparently this low fan noise is also present in the 2019 iMacs with the 65W TDP CPUs, so there's no escaping it. I'll see when I get it how much it bothers me, I hope I can get used to it (after all, we've been using computers with fans like vacuum cleaners for a long time... ).

Hah yeah, that's what I was thinking. Before 2012 I was using a PC which was a vacuum cleaner in deed! But I guess I am very spoiled with the silence of my iMac 2012.

I must say I'm getting used to the fan noise of the 2019. But I think they did a better job sound designing the fan noise in the 2012. It's a small price to pay for all the computing power the 2019 has. I am getting 2-5x faster render times in After Effects so I am very happy with my new machine.

 

[ferencav]

I ran the same render on both machines and my iMac 2012 stays at an average of 80° degrees. The 2019 heats up to about an average of 92° (showing in orange/red ). Is this what to expect from the new 2019? Just want to double check this is expected behaviour and my model is ok.

 

[WrightBrain]

I ran the same render on both machines and my iMac 2012 stays at an average of 80° degrees. The 2019 heats up to about an average of 92° (showing in orange/red ). Is this what to expect from the new 2019? Just want to double check this is expected behaviour and my model is ok.

This is consistent with all of the other benchmarks I've seen. The new chips run HOT. It's one of the main reasons I've been hesitating to buy one. Will it hurt the machine in the future? I don't know. But I do know extra heat can cause damage to components to computers. Also if the fan has to run more often you can get dust build up, which on an iMac you can't clean out.

As for recommendations to keep it cool. I've seen people report success with Turbo Boost Switcher to turn off Turbo Boost. You take a slight performance hit, but it may not be noticeable in real world testing. You can also manually turn the fans up while running intensive tasks (rendering, gaming, processing sound, etc.) using Macs Fan Control. Of course you have to be careful when adjusting settings, and running the fan more could increase the chances of dust accumulation.

Other tricks I've seen people mention are to put a fan under the "chin" of the iMac to force cool air in or put it on the back vent to help draw hot air out.

For me, I'm just not certain I want to buy something I have to jury rig cooling solutions for.

But I suppose you could always sell it in two years before the AppleCare runs out.

 

[ferencav]

This is consistent with all of the other benchmarks I've seen. The new chips run HOT. It's one of the main reasons I've been hesitating to buy one. Will it hurt the machine in the future? I don't know. But I do know extra heat can cause damage to components to computers. Also if the fan has to run more often you can get dust build up, which on an iMac you can't clean out.

As for recommendations to keep it cool. I've seen people report success with Turbo Boost Switcher to turn off Turbo Boost. You take a slight performance hit, but it may not be noticeable in real world testing. You can also manually turn the fans up while running intensive tasks (rendering, gaming, processing sound, etc.) using Macs Fan Control. Of course you have to be careful when adjusting settings, and running the fan more could increase the chances of dust accumulation.

Other tricks I've seen people mention are to put a fan under the "chin" of the iMac to force cool air in or put it on the back vent to help draw hot air out.

For me, I'm just not certain I want to buy something I have to jury rig cooling solutions for.

But I suppose you could always sell it in two years before the AppleCare runs out.

Thanks for your reply! It's good to know that these temperature readings are consistent with other benchmarks. That's exactly what I needed to know. Now I am confident to keep this machine. It is hot indeed, so time will tell if the components can handle all the heat.

The Turbo Boost Switcher is still a good option if I am going to worry about this in the future. An external fan is not an option in my opinion.

When idling or doing average day work, this machine runs about 10 degrees cooler than the 2012. It's only during heavy rendering the temperatures go into these extremes. Perfromance-wise I can recommend this machine very much. My last render finished in 43 min on my 2012 where the 2019 finished in 11 minutes. Very happy with this result.

 

[Bimmicus]

Temperature at the GPU diode regularly reaches 95-99 centigrade when the card is under load, with the fan going full blast. The games I run (World of Warcraft, Diablo III) are not what you'd call graphically demanding. Should I return this machine?

 

[mj_]

Or, instead of jury rigging some sort of concoction to keep a 95W CPU cool with a cooling system that was designed for 65W CPUs you could instead just get an iMac with a 65W CPU and not worry about temperatures and fan noise at all. I dare to say that most users are not going to notice the difference between the 65W i5-8500 or i5-8600 and the 95W i5-9600K. Yes, it might be a split second slower here and there but nothing to write home about. In return, it should remain MUCH cooler and quieter. Case in point: my 2017 base model (3.4 GHz i5) never exceeds 70°C under full load, and I have yet to witness the fan rev up above its 1,200 rpm base line.

The i5-9900K is a different story since it has two additional cores. Plus it is also the only one available with the optional Vega 48 GPU. Why? Because Apple said so.

 

[FuriousGallus]

They can be very graphically demanding, it all depends on the settings you're running them on. Let us know what they are and maybe it can shed some light on your situation.
Regarding the fans, as far as I've seen nobody was able to get them to run full blast even when benchmarking - so it would help if you could actually measure their RPM and post that too.
Also, if you're not running the i9, thermal performance could be worse compared with the i5. I've not seen temps from i5/Vega combinations posted yet.

 

[Bimmicus]

Processor is the 3.6Ghz i9. Max fan speed according to Macs Fan Control is 2700, and it regularly hits this limit when the GPU is under load. The CPU doesn't seem to be running particularly hot.

WoW is a mix of graphical settings, almost none of which are maxed or even close to it. I've been playing around with different settings to see how it affects GPU temp and nothing's made an obvious difference. Diablo III settings are identical to what they were on my old machine, and the game is not even running that well despite the GPU working overtime for god knows what reason. Again, I've tried changing various things and it seems to make no difference.

I basically need to know whether temperatures like this are in any way acceptable or merely a guarantee of problems down the road. The fan noise, while annoying, is something I can live with.

 

[WrightBrain]

Or, instead of jury rigging some sort of concoction to keep a 95W CPU cool with a cooling system that was designed for 65W CPUs you could instead just get an iMac with a 65W CPU and not worry about temperatures and fan noise at all. I dare to say that most users are not going to notice the difference between the 65W i5-8500 or i5-8600 and the 95W i5-9600K. Yes, it might be a split second slower here and there but nothing to write home about. In return, it should remain MUCH cooler and quieter. Case in point: my 2017 base model (3.4 GHz i5) never exceeds 70°C under full load, and I have yet to witness the fan rev up above its 1,200 rpm base line.

The i5-9900K is a different story since it has two additional cores. Plus it is also the only one available with the optional Vega 48 GPU. Why? Because Apple said so.

That is definitely a valid option to go with the 65w chip. The only issue I have is then you are stuck with a 4GB Radeon 575x. You can sorta upgrade it with an eGPU, but I've been hearing that it doesn't always benefit if you want to run it on your main monitor. It depends on how the application is written. Also I get resentful that if I want to have a reliable machine, I have to buy a machine with lesser specs. I'm so tempted to dump the whole thing to build a PC. I've already specced one out for less than $2,000 and I can repair it myself if any of the bits fail.

The part that bothers me the most is the SSD on the iMac. Apple charges approx $600 to $700 for a 1TB SSD. A Samsung 970 SSD NVMe is only $250. What the hell?

I noticed on a teardown that Apple uses SanDisk NVMe's. The 1TB in the pro line is $450 and that comes with a 5 year warranty. Figure that Apple gets them in bulk so they are even cheaper, how do you justify the $600 to $700 price tag?

 

[WrightBrain]

It is in line with how the current line of iMacs handle their thermals. Not a lot you can do I'm afraid.

 

[Bimmicus]

It's cool how my topic was merged into this one despite being about a very specific issue, and with my OP gone it seems unlikely I will get any further answers to my question. Very necessary, great modding.

 

[ferencav]

I basically need to know whether temperatures like this are in any way acceptable or merely a guarantee of problems down the road. The fan noise, while annoying, is something I can live with.

I don't know how your OP read, but I think we have quite the same question. I'm afraid only time will tell if these temperatures are a problem for the machine, but if someone has some extra insights I'm happy to hear them.

I'm still not liking the fan noise either, but I'm getting used to it. I think if it throttled in silence it was a much bigger problem for me.

 

[WrightBrain]

I don't know how your OP read, but I think we have quite the same question. I'm afraid only time will tell if these temperatures are a problem for the machine, but if someone has some extra insights I'm happy to hear them.

I'm still not liking the fan noise either, but I'm getting used to it. I think if it throttled in silence it was a much bigger problem for me.

There's no way to know. The 2017 iMac has been out there for two years with outrageous temps and there haven't been widespread failures. Sporadic ones, but not widespread.

There have been reports of dust getting caught in the lower corners of the screens, and I've seen a few screen failures, but not many. It may be three years or more before you see issues.

As for the question is it normal for your imac. Yes it is. Exchanging it for a new one won't get you better operating temperatures. It's just the state of iMacs now.

Heat DOES cause issues. Is it guaranteed it will in the 2017 and 2019 iMacs...nope. But PC makers don't recommend running CPU's higher that 70 to 80 for long periods of time.

 

[Bimmicus]

I don't know how your OP read, but I think we have quite the same question. I'm afraid only time will tell if these temperatures are a problem for the machine, but if someone has some extra insights I'm happy to hear them.

My question was specifically about the Radeon Pro Vega 48, which regularly hits temps of 95-99 degrees Centigrade on my machine even when running fairly old games.