My iMac i7 runs too hot!

[iemcj]

No point of getting i7 if it throttles to the performance of an i5 or worse than i5 if i5 runs cooler

Your info is wrong because these skylake processors are extremely difficult get to the point where it needs to throttle. Just doesn't happen. Many many many people have been posting youtube videos and repeatedly it's running much cooler than any previous years models in their torture tests. Last years imac had it happen sometimes where it would get to hot and need to slow down, the whole point of the skylake chips is running much cooler.

You are not running too hot. Your computer is doing exactly as expected, you're basically asking a pickup truck to haul a full load of gravel then act shocked when it revs up to do it. This is normal, and no, you're not going to get better performance under the i5. The i5 is going to get pushed to it's own limit even faster and therefore get just as hot, and it's going to STAY at that heat even LONG because it's not as good as those calculations as the i7 is.

Just stop worrying. You bought a high end piece of hardware and this is exactly what it's designed for. I have two cordless drills, I have a cheapy 20 dollar one I got from ace hardware and a very expensive contractor grade dewalt. The little is light and easy to use but after a few minutes it starts to warm up so I stop using it. It's low quality parts and putting a strain on it has a chance of wrecking it.

Contrast that with my 250 dollar contractor drill, I can use this thing for hours and even if it does get hot, I know it can handle it. It's purpose built, the guys who made it KNEW it was going to get used hard and so they used quality parts to make sure when it does heat up, it doesn't get wrecked. That's the same thing here. OF COURSE it's going to get warm, you're doing something very very cpu intensive. It's totally ok. It can handle it.

 

[Moriske]

Support Apple tells me that this would be wrong and suggested himself for an exchange.
Weird?

When I convert an entire audio folder (lossless to MP3), I also have 100% CPU and 100% Fan speed, noise.
Fan is at full power 100% ....... CPU +/- 96C, no breathing space left?

****Want someone to convince me, post pictures of a same configuration****
iMac 5k Late 2015
i7 4.0ghz m395

 

[cbautis2]

Support Apple tells me that this would be wrong and suggested himself for an exchange.
Weird?

When I convert an entire audio folder (lossless to MP3), I also have 100% CPU and 100% Fan speed, noise.
Fan is at full power 100% ....... CPU +/- 96C, no breathing space left?

****Want someone to convince me, post pictures of a same configuration****
iMac 5k Late 2015
i7 4.0ghz m395

It all depends on people's opinion. To me, if the cooling on A BRAND NEW machine can't keep the CPU below 90 degrees C at full load ON THE WORST scenario i.e. 30 degrees room temperature, it's a fail and that CPU shouldn't be offered as an option. Maybe if the machine is a year old then that's when heat issues starts to show up (i.e. full load very close to 100 degrees) since it's an indication of worn out thermal paste, but it's unacceptable to me for a brand new machine to operate at the Tjunction temperature of the CPU.

 

[Moriske]

To me, if the cooling on A BRAND NEW machine can't keep the CPU below 90 degrees C at full load ON THE WORST scenario i.e. 30 degrees room temperature, it's a fail and that CPU shouldn't be offered as an option. Maybe if the machine is a year old then that's when heat issues starts to show up (i.e. full load very close to 100 degrees) since it's an indication of worn out thermal paste, but it's unacceptable to me for a brand new machine to operate at the Tjunction temperature of the CPU.

Thnx
Well defined.

 

[h9826790]

I think you are right to be concerned. I found an Intel spec for a 3.3GHz i7 (from 2010 though):

http://www.intel.com/content/dam/ww...-desktop-processor-series-datasheet-vol-1.pdf

There's a chart on Page 73, "Processor Thermal Profile" and it maxes out at 68 degrees C. In other forum discussions I've seen estimates ranging from 65 to 77 degrees C, but not close to 100.

At least check with AppleCare.

Ar... that's i7, but not this generation, the spec is totally different. That 68 is applicable on my W3690 (which is basically the same chip as i7-9xx), but not the 6700k. Even though in the same generation, the official temperature limit can be quite different between models. If Intel says 6700k is good for 105C, then 100C is nothing to worry about (at least not for the CPU itself ).

Unfortunately that is not the solution
No DVDFab, HandBrake, etc .... pfffff

For Handbrake, rather than turn off HT, you may just add ":threads=6" (or =4, whatever you want) command in the advance section, that will limit Handbrake only use up to 6 thread of the CPU. So, you still has HT, all 8 thread still available to you, but effectively avoid Handbrake fully occupy your CPU.

This is what I often do to my machine, not for cooling, but leave 2 threads for something else. In my case, I limit Handbrake max at 10 threads, because I frequently run Handbrake continuously for >100 hours, and I want to reserve 2 threads for my Mac to give me same responsiveness for other ops. But in your case, it should help to cool down as well. I don't know if those encoding job is time critical for you, if not, you may simply limit it to use less core, and leave it in the background. That's how I use my Mac anyway.

 

[iemcj]

Support Apple tells me that this would be wrong and suggested himself for an exchange.
Weird?

When I convert an entire audio folder (lossless to MP3), I also have 100% CPU and 100% Fan speed, noise.
Fan is at full power 100% ....... CPU +/- 96C, no breathing space left?

****Want someone to convince me, post pictures of a same configuration****
iMac 5k Late 2015
i7 4.0ghz m395

Alright I have that computer you're talking about, what program you want me to use? Is it handbreak? That'll be the good test to see if it's just your machine having a real problem.

 

[NT1440]

It concerns me that the CPU taps the 100 ° C, I think at these temperatures it will not live long.
It is not my intention to ad several programs or abs to increase te fan speed.
I already restarted the program, but he did it again.

When I using "CPU Setter" turn off hyperthreading, the CPU will be cooler and the fans start spinning quieter.

So.....you haven't been keeping up to date on regular processor behavior in the last 5 years or so.

100C is not too hot for a processor, and given what you were doing is to be expected.

 

[Buerkletucson]

Just let the guy be......
He's determined his iMac is running to hot......he'll find out the replacement will be exactly the same.

Only remedy if he believes it an issue.......which is obvious by his replies, is to sell the iMac and get something that runs the temps he wants.

Just let him continue his path of mind over matter.

 

[antipodean]

Alright I have that computer you're talking about, what program you want me to use? Is it handbreak? That'll be the good test to see if it's just your machine having a real problem.

I have a 2015 i5 3.3GHz/395/32GB/1TB SSD, so that should provide you with a comparison all else being the same apart from CPU. Nothing to encode in Handbrake right now, but I ran the Prime 95 "torture test" on both my iMacs (see screen shots). Subjectively, the 2015 i5 was much quieter, temps were lower and fan didn't spin up as much. The 2013 iMac is a Haswell 3.5 GHz i7 (I think it's a 4771)/780M/32GB/1TB SSD.

Conclusion: as expected the Haswell i7 generated more heat than the Skylake i5. In both cases, the iMac's cooling system kept the CPU core temps <90C most of the time, but this required high fan speed for the i7 iMac.

 

[DaakuMaujii]

I'm more worried about the cooling and noise that are already running at full power, without any reserve in the cool days

At this time, it is here at home 21C.
In the spring / summer is here quickly 26C, and the fans are now already running without reserve

Agreed. How the iMac will perform during the warm summer days is something I'm curious about as well. It wouldn't be much fun to hear a constant humming of the fans. The temperature of the CPU won't increase beyond its safety regulation point, but chances are the CPU will throttle more than during winter.

Regarding throttling of the CPU. At my office I have a Retina iMac with Core i5 from 2014 and did some experiment. I noticed that at full load (all four cores) it would not throttle at all. In fact, it would run slightly above baseline performance; i.e. small turbo boost. That means there was still headroom left before any throttling would occur. It does cause the fans to kick in though, and maybe for home use it would have been more pleasing to not turbo boost at all and have lower fan speeds resulting in less noise.

No point of getting i7 if it throttles to the performance of an i5 or worse than i5 if i5 runs cooler

My Macbook Pro (Mid 2014 with 2.8GHz Core i7) shows similar behaviour as the iMac Core i5 at my office during heavy load; slight turbo boost under heavy load, no throttling of the CPU.

It idles at 0.8GHz with temperatures a little below 40˚C.
With only a single core load it turbo boosts to 3.8GHz with slight increase in fan speed and temperatures around 80 to 90˚C.
Two cores loaded, and it turbo boosts to 3.5 to 3.6GHZ, temperature rises to 98˚C and fans speed up audibly.
A third core load and turbo boost drops to 3.3GHz, fans go to max to keep the temperatures at max 100˚C.
Another core load and turbo boost is down to 3.0 to 3.1 GHz, temperatures actually drop to 97˚C.
Fifth 'core load' (we have hyper threading after all), no change in turbo boost or temperature.
Sixth 'core load', turbo boost is limited to 3.0GHz, temperature remains at about 96˚C.
Seventh 'core load', no change.
Eight 'core load', turbo boost between 2.9 and 3.0GHz.

At this point system load is at 97% (all cores and hyper threading nearly completely used). Any extra load beyond this point remains the same: turbo boost between 2.9 and 3.0GHz and temperature between 94 and 98˚C, it actually shows a wave pattern, as it recovers in temperature it increases the frequency and vice versa.

In conclusion: no CPU throttling even though it quickly hits the >90˚C range. There is even a slight turbo boost under full load; also no full 4.0GHz turbo boost with only a single core load but only 3.8GHz. This is for an incredibly thin Macbook Pro where there is no difference in TDP between the CPU options. The extra processing power certainly pays off.

I'm looking forward to the iMac with Core i7 and will be performing the same test. There is quite a difference in TDP between the Core i5 and the Core i7 for the iMac, but the benchmarks thus far are very promising, especially the multi-core benchmarks.

 

[cbautis2]

Agreed. How the iMac will perform during the warm summer days is something I'm curious about as well. It wouldn't be much fun to hear a constant humming of the fans. The temperature of the CPU won't increase beyond its safety regulation point, but chances are the CPU will throttle more than during winter.

Regarding throttling of the CPU. At my office I have a Retina iMac with Core i5 from 2014 and did some experiment. I noticed that at full load (all four cores) it would not throttle at all. In fact, it would run slightly above baseline performance; i.e. small turbo boost. That means there was still headroom left before any throttling would occur. It does cause the fans to kick in though, and maybe for home use it would have been more pleasing to not turbo boost at all and have lower fan speeds resulting in less noise.



My Macbook Pro (Mid 2014 with 2.8GHz Core i7) shows similar behaviour as the iMac Core i5 at my office during heavy load; slight turbo boost under heavy load, no throttling of the CPU.

It idles at 0.8GHz with temperatures a little below 40˚C.
With only a single core load it turbo boosts to 3.8GHz with slight increase in fan speed and temperatures around 80 to 90˚C.
Two cores loaded, and it turbo boosts to 3.5 to 3.6GHZ, temperature rises to 98˚C and fans speed up audibly.
A third core load and turbo boost drops to 3.3GHz, fans go to max to keep the temperatures at max 100˚C.
Another core load and turbo boost is down to 3.0 to 3.1 GHz, temperatures actually drop to 97˚C.
Fifth 'core load' (we have hyper threading after all), no change in turbo boost or temperature.
Sixth 'core load', turbo boost is limited to 3.0GHz, temperature remains at about 96˚C.
Seventh 'core load', no change.
Eight 'core load', turbo boost between 2.9 and 3.0GHz.

At this point system load is at 97% (all cores and hyper threading nearly completely used). Any extra load beyond this point remains the same: turbo boost between 2.9 and 3.0GHz and temperature between 94 and 98˚C, it actually shows a wave pattern, as it recovers in temperature it increases the frequency and vice versa.

In conclusion: no CPU throttling even though it quickly hits the >90˚C range. There is even a slight turbo boost under full load; also no full 4.0GHz turbo boost with only a single core load but only 3.8GHz. This is for an incredibly thin Macbook Pro where there is no difference in TDP between the CPU options. The extra processing power certainly pays off.

I'm looking forward to the iMac with Core i7 and will be performing the same test. There is quite a difference in TDP between the Core i5 and the Core i7 for the iMac, but the benchmarks thus far are very promising, especially the multi-core benchmarks.

Seems normal to me. As long as frequency is at or above 2.8 GHz full load, no worries at all. If will throttle though when core (not package) temps reach 101 degrees

 

[Moriske]

Alright I have that computer you're talking about, what program you want me to use? Is it handbreak? That'll be the good test to see if it's just your machine having a real problem.

Thanks
Like please just test the next program.

For audio file conversion:
dBpoweramp Music Converter: https://www.dbpoweramp.com/dmc.htm
I convert an entire folder (500 songs) lossless FLAC to Apple Lossless (ALAC) = full CPU load.

 

[Moriske]

Alright I have that computer you're talking about, what program you want me to use? Is it handbreak? That'll be the good test to see if it's just your machine having a real problem.

Thanks
Please just test the next program.

For audio file conversion:
dBpoweramp Music Converter: https://www.dbpoweramp.com/dmc.htm
I convert an entire folder lossless FLAC to Apple Lossless (ALAC) = full CPU load.

 

[loekf]

It's still funny. In the far far past, I remember AMD motherboards having a thermal shutdown when the CPU reached a temp above 85 celsius. Desktop CPUs even with stock cooler never run above 50-60 celsius. At least AMD FX CPUs, which take a lot of power and have a 125W TDP.

As long as you don't get a thermal shutdown I would say your iMac behaves within design parameters (its thermal envelope).

AFAIK, Intel CPUs have a maximum junction of 130 celsius when all processing is stopped.

Above 90-100 celsius throttling kicks in. Can you see clockspeed varying over time ?

 

[AlifTheUnseen]

Sooooo you're thinking that if you send in a less powerful chip and as it to do that same super demanding task that it's going to perform BETTER? One of two things will happen. It'll A, run hotter and take longer and therefore stay hotter for longer or B, run just as hot and take far longer and therfore keep your system at a high temp for much longer. Either way using an inferior chip is in no way a solution haha.

Look, this is operating the way it's supposed to. This is a carefully constructed imac, not a thrown together modular pc. It can handle those temps. If it becomes a problem it has a magical ability to crank up the fan automatically and stay at a safe temp. If that isn't enough then it can slow itself down a few htz to ensure safety. You're not going to be able to melt your computer, people tried it with last years rimac (which DID run much hotter), this system will be fine.

Again, if you're that worried about it then download smcfancontrol and manually raise your fan speed. You're complaining, then we offer solutions and you turn them down. We then tell you it's really not a problem and you're not happy with that either. I don't know what else to tell you bro?

You clearly have no clue what you are talking about. That's ok, I don't mind, but I take issues if you use a language like you did and showed a general lack of empathy, understanding and politeness. Happily, the OPs didn't take your rants seriously and showed a picture of the T readings with hyperthreading turned off.
It's clear that higher temperatures will result in a higher thermal stress. Will it be fine in case of this iMac? Or will the high temperatures slowly gnaw at the fine structures until the weakest links break? Nobody, even Apple, has a long-time experience with so densely packed iMacs as the maxed-out iMacs of this and last year. I think everybody should be getting AppleCare just in case...

 

[EnesM]

It all depends on people's opinion. To me, if the cooling on A BRAND NEW machine can't keep the CPU below 90 degrees C at full load ON THE WORST scenario i.e. 30 degrees room temperature, it's a fail and that CPU shouldn't be offered as an option. Maybe if the machine is a year old then that's when heat issues starts to show up (i.e. full load very close to 100 degrees) since it's an indication of worn out thermal paste, but it's unacceptable to me for a brand new machine to operate at the Tjunction temperature of the CPU.

30 degrees room temperature? Your iMac is in a sauna?

 

[Moriske]

Above 90-100 celsius throttling kicks in. Can you see clockspeed varying over time ?

CPU is under full load slightly down with a temperature of +/- 96 degrees!!!

Today, the iMac goes via UPS back for exchange to the same configuration.
Wondering if this is about an exemplary case or not?

 

[hifimacianer]

30 degrees are not unusual in a hot summer.
We had a really hot summer in Germany this year, with night temperatures >25 degrees.
Even in our appartment with 40cm thick brick walls the temperatures had a peak @ 28 degrees.
I have friends living in roof apartments with temperatures of more than 35 degrees!

And since we usually don't have aircon in private homes, these temperatures can happen from time to time.

 

[chevalier433]

Just now I was converting a Bluray movie to an MKV file with DVDFab.
A minute later the fans of the iMac 27 "full 5K started to blow and I read the following details of the program TG Pro. As a precaution I aborted the operation prematurely.

These temperatures I've never seen before in my Windows PC?

Data from my iMac be next.
Processor: i7 6700K
Memory: 8GB
SSD 512GB
Graphics: AMD Radeon R9 M395 2GB

Just now I was converting a Bluray movie to an MKV file with DVDFab.
A minute later the fans of the iMac 27 "full 5K started to blow and I read the following details of the program TG Pro. As a precaution I aborted the operation prematurely.

These temperatures I've never seen before in my Windows PC?

Data from my iMac be next.
Processor: i7 6700K
Memory: 8GB
SSD 512GB
Graphics: AMD Radeon R9 M395 2GB

Dont get paranoid you are lucky you have a dream computer enable hyper threading again and use it as hard as you can is what you paid for.Your processor as previous generation Intel processors even high overclocked need years of hardcore use for performance to degrade.As a previous i7 iMac owner I was getting paranoid in the begining with the temps as you coming from pc.I used mine for pro video editing and encoding every day all day as hard as many jobs I had.I keep it for 4 years never never had a reliability problem,I sold it as new and I really miss it now.

 

[Moriske]

I want to compare the iMac i5 to the same test as the i7, so i went to the Apple Store.

Keeping in mind with the temperature indoor of 21°C and a brand new iMac, I wanted to see if the ventilation was enough to cool down the CPU when he was occupied for 100% and if there was still enough reserve to continue at full speed with the process.

Because the Apple Store only had an iMac 5K of the late 2014 in demo ( Haswell i5 3.5GHz 4690 without K, TDP 84 Watt) with a little higher TDP than the iMac 5KI of the late 2015 ( Skylate 3.3GHz 4690 without K, TDP of 65 Watt), it was the test worth.

I was very supprised with these results

There was such a big difference, also cooling of the processor and the noise of the ventilation. With this configueration of the i5, with 100% CPU load, was hardly audible.

CPU temp with 100% load:
i5 +/- 75°C
i7 +/- 97°C (cpu throttling).

Speed fan:
i5 +/- 1.195 rpm (gently waving cooling).
i7 +/- 2850 rpm (at continuously maximum speed = no reserve).


iMac 5K (late 2014) Haswell i5 3.5GHz 4690 without (K) TDP 84Watt + M290X



iMac 5K (late 2015) Skylake i7 3.3GHz 6600 without (K) TDP 95Watt + M3955

 

[antipodean]

Your results are similar to those I posted above, ie i7 uses more fan than i5 when both are under max load.

 

[shaunp]

Just now I was converting a Bluray movie to an MKV file with DVDFab.
A minute later the fans of the iMac 27 "full 5K started to blow and I read the following details of the program TG Pro. As a precaution I aborted the operation prematurely.

These temperatures I've never seen before in my Windows PC?

Data from my iMac be next.
Processor: i7 6700K
Memory: 8GB
SSD 512GB
Graphics: AMD Radeon R9 M395 2GB

This is exactly why all-in-one computers are such a terrible idea. My nMP never runs hot, nor does my PC. And I can choose my own monitor...

 

[Sirmausalot]

i just made

This is exactly why all-in-one computers are such a terrible idea. My nMP never runs hot, nor does my PC. And I can choose my own monitor...

i just edited a 45 minute movie on my 'terrible' all in one 5k iMac. yeah, sensors said it was toasty when i encoded 4k to h264 in twenty minutes. but the case wasn't hot to the touch nor did the machine emit smoke. i heard the light whirring of fans which practically put me to sleep. (actually, i left the room to grab something to eat)

 

[dyn]

This is exactly why all-in-one computers are such a terrible idea. My nMP never runs hot, nor does my PC. And I can choose my own monitor...

For something that costs about twice as much it better be!

 

[Moriske]

i just made

i just edited a 45 minute movie on my 'terrible' all in one 5k iMac. yeah, sensors said it was toasty when i encoded 4k to h264 in twenty minutes. but the case wasn't hot to the touch nor did the machine emit smoke. i heard the light whirring of fans which practically put me to sleep. (actually, i left the room to grab something to eat)

The point is that the fans in this colder days does not have any reserve on board.
The result is that the cooling / noise is already at its maximum RPM.