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My iMac i7 runs too hot!
- Thread starter Moriske
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So they actually replaced your iMac due to the temperature situation? You went from an i7 iMac to another i7?
Last night I was testing out my new imac temperature and saw the CPU was at 117 degrees. I was freaking out for 2 minutes before I realized it was in Farenheit...
Hello,
I'm in the same boat as you (handbrake encoding), I'll get a 3.3 i5 if the 4.0 i7 drops to 3.3 and the 3.3 does not drop. For your second image below, is that the 4.0 i7 and is it down clocking? If it's the i7 and not down clocking, then I will go with the i7.
Also, has anyone looked at how Apple applied the thermal paste on the 2015 imacs? My 2011 MacBook had it caked on and initially ran at 100C, but after cleaning that up and applying some AS to it, it now will never go over 90, even when under 100% load...no throttling either.
I'm in the same boat as you (handbrake encoding), I'll get a 3.3 i5 if the 4.0 i7 drops to 3.3 and the 3.3 does not drop. For your second image below, is that the 4.0 i7 and is it down clocking? If it's the i7 and not down clocking, then I will go with the i7.
Also, has anyone looked at how Apple applied the thermal paste on the 2015 imacs? My 2011 MacBook had it caked on and initially ran at 100C, but after cleaning that up and applying some AS to it, it now will never go over 90, even when under 100% load...no throttling either.
Luckily the exchange to a new one was worth.
My final measurements have shown very clearly that the foregoing exemplary model, nevertheless had a problem around cooling.
As you saw in the 1st model at 100% CPU load, the Fanspeed (2850 RPM) runned continuously at its maximum.
In this 2nd model with a 100% CPU load, luckily the Fanspeed gets no higher than 2280 RPM. Also it strikes me at this 2nd model, that the cooling unit at 100% CPU load is now much less.
I can therefore say that there is enough reserve to cool the CPU and the noise level is also clearly calmer.
Finally I can enjoy this iMac i7 for its purpose, and I will not be stressed any more, because it is a much quieter running fan.
100% speedfan (bad cooling)
Speedfan (silent cooling with reserve)
I still get concerned when it goes over 110 F.
I am under most condition able to keep it around 100 F.
Intensive operations can push it to 120 F but because I keep the ambient room temp lower than the rest of the house the computers stay happy.
There is a reason why computer rooms in schools and businesses generally have their own air conditioning and filtration systems. But even with that, unless they are in certified clean rooms .... things get dusty, and dust buildup adversely affects cooling ability.
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Thnx
Yes, after a few days.
Finally here an silent iMac where the cooling unit at 100% CPU load, has the necessary reserves to work full power.
Good that the replacement works for you.
We use software to keep the fans running .... it's nice to know they work!
Room is air conditioned so the cooling air they get is proper ..... this helps quite a bit.
Handbrake ripping of a DVD can be intensive.
Our iMacs have the internal optical drives and they add to heat generated.
I used to work in commercial computer rooms and they were always colder than the other areas, like factory floor and general offices. Computers like colder air.
About those equipment rooms...there used to be the idea that you had to cool them down considerably (equipment was thought to have a temperature around 25C and shutdown when 30C or 35C was reached in order to protect the hardware). This also increases the carbon footprint, not very environmental friendly. This has sparked a discussion about the necessity of cooling things down and to what temperature you need to cool it down. We are now seeing that most equipment rooms are now warmer because we know that there is no need to cool them down considerably (the max temperature has now moved up to 40C-ish). Another thing changed as well: instead of cooling the entire room or the entire rack from bottom to top they now position the racks in such a way that there is only 1 corridor that they have to cool. The equipment will draw the cool air from the front and expel the hot air at the back into the room (which isn't cooled at all). Saves enormous amounts of energy and has no impact on the hardware.
Our ideas about what temperature is the max for hardware has changed due to experimentation and research.
Our ideas about what temperature is the max for hardware has changed due to experimentation and research.
So they are still chilling/cooling/air conditioning the air going into the systems.
Just channeling it more direct into the system than into the entire room to be more efficient.
Sounds like the setup I have here ..... albeit I did it on the 'home brew' cheap side.
But how many people are going to install a window AC in the wall with duct work channeling it to the equipment racks.
I have one 5000 BTU AC window unit that feeds into ductwork, that then is fed into five equipment racks.
But that room is not were the iMacs reside.
Just channeling it more direct into the system than into the entire room to be more efficient.
Sounds like the setup I have here ..... albeit I did it on the 'home brew' cheap side.
But how many people are going to install a window AC in the wall with duct work channeling it to the equipment racks.
I have one 5000 BTU AC window unit that feeds into ductwork, that then is fed into five equipment racks.
But that room is not were the iMacs reside.
I'm glad the solution worked. This thread brought back memories of my brother-in-law sitting in his underwear in his bedroom, sweating profusely, huddled over his over-clocked PC running Everquest in his room. I'll bet his room heated up to 90 F or higher when he was playing. I don't think he ever worried about his core temperatures
FWIW, I noticed that with my mac mini, the room temperature makes a huge difference in fan noise. Not that I cool my house more because of it, but it's definitely a factor.
FWIW, I noticed that with my mac mini, the room temperature makes a huge difference in fan noise. Not that I cool my house more because of it, but it's definitely a factor.
110 F underload isn't bad, when I was building PCs 150F was common. I usually start getting a little concern with anything over 150F (66C). That is if it stays that long. I look at signs other than temperature when it gets above the comfort limit, like computer shutting down or freezing up forcing you to reboot.
Convert your info to C and use this older rule:
80C=CPU will last the life of your pc, during this time, it was defined as 10 Years.
Half your CPU life for every 5C hotter it runs continuously
85C=5 years
90C=2.5 years
95C=1.25 years
100C=.75 years...my last dell was designed with this limit for cont. running...I had to replace it seven times before the warranty ran out and Dell would no longer honor it.
Again, this is continuous running.
Has anyone checked to see if the thermal paste is too thick on this?
Die temps are now at a max of 110C so the info is very outdated. We've come a long way
As of the 6th Generation i7, intel is still saying:
"Sustained Core temperature greater than 80C is too hot for ultimate stability, performance and longevity."
Excessive Vcore and temperatures will result in accelerated "Electromigration" - https://www.google.com/?gws_rd=ssl#q=Electromigration - which prematurely erodes the traces and junctions within the processor's layers and nano-circuits. This will eventually result in blue-screen crashes, which will become increasingly frequent over time.
Below is a list of Tjunctions for processors.
6th Generation 14 nanometer: i7 6700K / i5 6600K (TDP 91W / Idle 2W)
Tcase (CPU temp) = 63C
Tjunction (Core temp) = 68C
Tj Max (Throttle temp) = 100C
5th Generation 14 nanometer: i7 5775C / i5 5675C (TDP 65W / Idle 2W)
Tcase (CPU temp) = 71C
Tjunction (Core temp) = 76C
Tj Max (Throttle temp) = 96C
4th Generation 22 nanometer: i7 4790K (TDP 88W / Idle 2W)
Tcase (CPU temp) = 74C
Tjunction (Core temp) = 79C
Tj Max (Throttle temp) = 100C
4th Generation 22 nanometer: i5 4690K (TDP 88W / Idle 2W)
4th Generation 22 nanometer: i7 4770K / i5 4670K (TDP 84W / Idle 2W)
Tcase (CPU temp) = 72C
Tjunction (Core temp) = 77C
Tj Max (Throttle temp) = 100C
3rd Generation 22 nanometer: i7 3770K / i5 3570K (TDP 77W / Idle 4W)
Tcase (CPU temp) = 67C
Tjunction (Core temp) = 72C
Tj Max (Throttle temp) = 105C
2nd Generation 32 nanometer: i7 2600K / i5 2500K (TDP 95W / Idle 8W)
Tcase (CPU temp) = 72C
Tjunction (Core temp) = 77C
Tj Max (Throttle temp) = 98C
Previous Generation 45 nanometer: i7 860 / i5 750 (TDP 95W / Idle 12W)
Tcase (CPU temp) = 72C
Tjunction (Core temp) = 77C
Tj Max (Throttle temp) = 100C
Previous Generation 45 nanometer: i7 920 D0 (TDP 130W / Idle 12W)
Tcase (CPU temp) = 67C
Tjunction (Core temp) = 72C
Tj Max (Throttle temp) = 100C
That's what you get when you prioritize design over function.
Apple removed all of the vents that were at the top of the iMac case and all we are left with is a thin slit on the bottom that is used as both the inlet and exhaust of air; all driven by an anemic fan.
Apparently someone at Apple forgot that hot air rises and jamming several hundred watts of electronics into a closed box with inadequate ventilation is a bad idea and will stress the components i.e. shorten their lifespan. But hey, it's thin and looks pretty from the back.
If I was to purchase a 5k iMac the first thing I would do is cut the case open (it's glued shut) and drill two 1-2 inch holes in the top left and right corners.
My 2015 iMac runs 20° cooler than the 2010 I mac I also use elsewhere (28°/48°). Both use a quad core processor.
Yes, the new 5k runs cooler than the previous model and they adjusted the fan speed. This is mainly due to the Skylake processor running cooler.
But regardless it's not healthy for the CPU / GPU to run at such high temperatures for prolonged periods of time.
All Apple needs to do in increase the ventilation in the case and a lot of these issues would be reduced or go away all together.
Being a sealed unit, I don't think this would be a good idea. I am sure vents on the bottom were a deliberate functional design choice. Ventilation anywhere other than on the bottom of the unit would cause dust falling on the machine or around the machine to be sucked inside. iMacs can't easily be cleaned, so I think accumulated dust would become a problem more quickly.
The 2015 21.5" 2k model runs very cool. Maxing out all four cores encoding high bit rate video footage gives me a sustained temp of 88°. That is the highest I have seen from it. The 4K and 5K models may not yet be ready anything less than casual use as an entertainment device...but that is what you get with Apple - very nice, disposable machines that may not be ready for prime time. That's part of why I stuck with the older design.
Hot air rises.
Take a look at the slit on the bottom. it's about 5mm wide and acts both as inlet and exhaust driven by a small fan. This was a purely an aesthetic decision and is something we've seen across the entire Apple product line in the past 3 years.
It's also a problem with the 12 core/ D700 Mac Pro. Reports of the GPU frying itself under heavy use due to thermal failure are not uncommon. Again, a design decision where form was given priority over function.
Dust primarily accumulates on inlets, not exhausts. The vents on the top are (were) exhaust vents and any falling dust would have been blown away by the force of the air being expelled and it's thermal characteristics.
The real problem with dust and the 5k iMac is that the case is taped shut making it difficult or impossible to clean any existing vents and fans. Unless you are willing to slice trough the tape and then reseal it you will have to send the machine to Apple for cleaning and pay a service charge. This was not a problem when Apple used screws.
88 C is not good in the long term. There are also other electronics in there besides the CPU. Electronics do not like heat.
With the unit turned off dust is still going to fall in holes set on the top or maybe on the sides of the machine.
Of course. As I said, 88° is the highest temperature I have seen. The system idles at 28° under normal use. It might hit the low 30's. These are very low numbers.
The current design is fine as long as the system is equipped with and adequately cool processor. The 4K and 5K iMacs may have been released before their time - before adequate processors were available.
Of course. As I said, 88° is the highest temperature I have seen. The system idles at 28° under normal use. It might hit the low 30's. These are very low numbers.
The current design is fine as long as the system is equipped with and adequately cool processor. The 4K and 5K iMacs may have been released before their time - before adequate processors were available.
Vents on the top are not a problem due to falling dust, unless you live in an area plagued by sandstorms. And certainly not with an additional vent at the top that is circa 5mm wide. Any small amount of dust that accumulated would be blow out when you started the machine.
I'm not Jony Ive, but I did study industrial design. Vents on the top are not a problem.
The average user may be able to get away with those kind of temperatures because they only hit them occasionally and for short periods of time, but for someone using their machine on a regular basis for editing or anything else that pushes the processor to these temps for hours at a time, day after day, this is a problem.
The only reason we have seen a temperature drop in the new 5k is because of Skylake and the drop is about 10 C. The ventilation is still inadequate and it's running too close to the thermal limit. It's a problem caused by a decision to prioritize form over function which is a massive FAIL. Sorry, that's just the way it is.
Of course vents on the top of this machine would cause falling dust to slip inside. It doesn't take an industrial designer to understand the effects of gravity.
It would be 5mm wide. Enough dust to choke a machine is not going to fall into a 5mm slot especially when it is an exhaust blowing hot air. Remember Physics 101? Heat rises? You can raise an entire balloon carrying people with hot air, let alone a few dust particles.
Look around your house. Many appliances have vents on the top BECAUSE HEAT RISES. That's the entire concept behind the cooling system on the Mac Pro. Its essentially an open top machine with a fan drawing cool air in from the bottom and expelling hot air through the top.
But whatever makes you feel better about your purchase.
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