Desktops use a very huge air cooler with lots of fins to cool this chip. Even then, temps still reaches above 70 degrees even with diamond thermal paste applied. It's normal for this i7 chip to get 100 degrees since it's in an iMac enclosure. No matter what thermal paste you put, cooling a 90 watt chip on a enclosure like iMac is really hard. Best bet is to lower the clock modulation with an app.
Got a tip for us?
Let us know
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
My iMac i7 runs too hot!
- Thread starter Moriske
- Start date
- Sort by reaction score
Desktops use a very huge air cooler with lots of fins to cool this chip. Even then, temps still reaches above 70 degrees even with diamond thermal paste applied. It's normal for this i7 chip to get 100 degrees since it's in an iMac enclosure. No matter what thermal paste you put, cooling a 90 watt chip on a enclosure like iMac is really hard. Best bet is to lower the clock modulation with an app.
I think you misread my question. I understand those temps will exist in an iMac regardless of paste. I was curious if anyone knew the type. If you have an Intel chip reaching 100c on a regular basis at the temp sensor you'll want to only be using the highest quality paste to slow down it drying out and cracking and such.
Hard to tell, but I'm guessing it's a stock gray paste. Diamond paste are very viscous and sticky while cheap paste are much more fluid.
Thanks for the info
If the i5 3.3GHz (6600k) becomes less hot and the fans are less audible, this is my choice, even though I will have to give up something to performance.
In order to avoid mistakes!
**My Compare this involves the i5 3.3GHz and not the slower i5 3.2GHz**
Don't even worry about your Mac running too hot. They are selling you something they spec'd to be safe. If anything, push it as hard as possible during the warranty period to confirm it won't break. You shouldn't have to babysit your computer. If it breaks if you don't, Apple really screwed up and they are going to be paying a lot more on fixes.
IMac stands in the living room!
It's not just about the heat, but also the noise during long CPU loads. This noise bothers not only me, but unfortunately also the other family members here in the living room.
I just want a quieter iMac!
Only solution seems to me to choose the i5 3.3GHz (6600k) + AMD M395.
The i5 3.2GHz is just too light.
It's not just about the heat, but also the noise during long CPU loads. This noise bothers not only me, but unfortunately also the other family members here in the living room.
I just want a quieter iMac!
Only solution seems to me to choose the i5 3.3GHz (6600k) + AMD M395.
The i5 3.2GHz is just too light.
If you want a quieter Mac, buy a Mac Pro, or stop converting files. What did you honestly expect with the current enclosure that the iMac has?
In comparison, I had my 3.4 Ghz i7 2011 iMac run Handbrake for 20 hours yesterday. It never went above 68 degrees celsius, even though it used 800% CPU. The enclosure just have that much more room for air flow. And the fans were just noticeable.
In comparison, I had my 3.4 Ghz i7 2011 iMac run Handbrake for 20 hours yesterday. It never went above 68 degrees celsius, even though it used 800% CPU. The enclosure just have that much more room for air flow. And the fans were just noticeable.
My Mac Mini 2.3GHz i7 is even quieter than the iMac, also in strong video processing.
So may I as a buyer at these prices still expect the same!
I send this i7 iMac certainly back to Apple!
Last edited:
Hmmm, let us know if the new device has the same problems. I'm in the fence to order the same iMac as yours but with the M395X. But I really need the I7 for 4K editing. So I really hope the fix it.
http://www.intel.com/content/dam/ww...sktop-6th-gen-core-family-datasheet-vol-1.pdf
P. 94. Tjmax of Skylake-S processors is 100 degree Celsius. Tjmax is the point where thermal throttling starts kicking in, attempting to keep the processor temperature below Tjmax. If it fails to do so, overheat protection will kick in and shutdown the system.
So as long as the iMac does not shut itself off, it is normal. It has mechanism to prevent it from burning itself. You can say the heat dissipation is not good enough though, but it is unlikely the processor's fault as it is doing its job to keep the temperature down.
By the way, turning off Hyperthreading results in reduced temperature is not something strange either. In this case, one uses less computing resources, thus resulting in lower dynamic power and subsequently less heat generated. That's it.
Last edited:
Next week the new iMac i7 will arrive here, so I will keep you informed.
Look at this.
Here's a picture where I copy the i5, while putting the i7 hyperthreading off.
The fan works here like my Mac Mini, with a gentle breeze and if it were necessary, he has even more reserve in store for the CPU during some hot days to cool
Look at this.
Here's a picture where I copy the i5, while putting the i7 hyperthreading off.
The fan works here like my Mac Mini, with a gentle breeze and if it were necessary, he has even more reserve in store for the CPU during some hot days to cool
If we forget the high CPU temperature for a while.
My problem is still the noise of the fans, that concerns me and remind me always that the temperature will be to high!
This is not really within my expectations
For the hardware experts!
When I use the "CPU Setter" hyperthreading off, get the CPU cooler and the fans are going to run a lot quieter?
If this is the solution ..... may I compare this change with the i5 Processor: 3.3 GHz?
There's not much can do about the fans. You can disable them, there are apps that will give you control of fans and fan speed, but I would not recommend them as you run the risk of truly overheating the processor and components on your motherboard, and when that happens, well you have a large expensive paperweight on your desk.
Last edited:
This is interesting - my Mac mini with 2.6 GHz i7 (quad core) is definitely louder than my new i7 iMac when the fan ramps up to full speed.
I did some similar testing of video encoding, and watched my iMac CPU temperature also hit 99-100C. The fan ramped up and kept it from going above that, just as designed. It was certainly audible, but as I said, definitely quieter than my Mac mini at full load. I believe everything is working as designed; I would expect identical performance from your replacement iMac, and I doubt anything is wrong with the current one (unless your fan really is louder than it should be).
3 years of frequent similar processing loads on my Mac mini and it's working just fine. I expect the same and more from this iMac.
Thanks for the info
If the i5 3.3GHz (6600k) becomes less hot and the fans are less audible, this is my choice, even though I will have to give up something to performance.
In order to avoid mistakes!
**My Compare this involves the i5 3.3GHz and not the slower i5 3.2GHz**
I can't personally speak for Skylake CPU's but here is my Haswell i5 3.4ghz. Its been encoding for about 20 minutes, max was 84 which is the highest it will get, intake air temp is 19.83c measured with an AprilAire weather station which should be within 1 degree F.
That encode is using the VerySlow preset btw so thats not a very accurate way to compare speed but I think its safe to say faster chips are faster...
Last edited:
I can't personally speak for Skylake CPU's but here is my Haswell i5 3.4ghz. Its been encoding for about 20 minutes, max was 84 which is the highest it will get, intake air temp is 19.83c measured with an AprilAire weather station which should be within 1 degree F.
View attachment 597935
That encode is using the VerySlow preset btw so thats not a very accurate way to compare speed but I think its safe to say faster chips are faster...
Maybe the 14nm die shrink is too dense. However clock for clock, skylake runs cooler and faster even with die shrink. But overall skylake generates more heat due to being at a higher frequency state than haswell during video encoding.
Then again that assumes that each chip are equal in efficiency, i.e. doesn't factor in the silicon lottery. Some skylake i7 chips will run cooler than others due to the silicon lottery
Wow. I have never seen someone BUY a slower computer, because their faster one is too fast for their expectations.
Is because you do not read what is written
Ventilation is in the red, with no reserve!
CPU at +/- 95C and is throttling!!!
If you can't set the number of cores used by the application: create a virtual machine, assign it only a single core, and have a blast. Performance will only be about a quarter of what you would get with all four cores, but the load on your machine will be lower, resulting in lower temperatures and quieter fans.
Although I wouldn't worry too much about the high temperatures. Yes, 100˚C sounds high, but remember this is only a very local measurement at the actual cores of the CPU. In a tightly-packed Macbook Pro the CPU cores quickly reach ~98˚C, but the CPU proximity remains at about 55˚C (about 20˚C increase compared to idle; this number is roughly equivalent to heat sink / CPU casing temperatures reported by most desktops). What about the SSD and batteries in the Macbook? They increase with only 1˚C to 28˚C. It's like lighting a cigarette lighter in a room. The flame is hot, but the rest of the room in not melting away.
Regarding all these worries about high temperatures. I'm not an electrical engineer, but my guess for all these worries is that back in the old days with electrolyte capacitors high temperatures (say >65˚C) would drastically reduce the lifespan of your system as it could potentially cause the capacitors to rupture due to increased pressure caused by the liquids. However, with miniaturisation of electronic components came the solid-state capacitors that no longer use liquids that can come to a boil at high temperatures. Consequently, these capacitor have been rated at a safe operating temperature of up to 125˚C. Safe operating temperatures defined by Intel are guaranteed by throttling the CPU.
P.S. I'm not saying temperature does not have an effect of life span of electronics, but I don't think the impact is as significant as it used to be. I love to let machines crunch numbers and process data, and I've had many machines operate at high temperatures. The best memory is of a small form-factor Shuttle casing with a Pentium D 950 (about 135W if I recall correctly) that would run at >105˚C (back in those days the software tool would only show graphs going as high as 100˚C). It was packed in a small wooden cupboard, and when you got close you could actually feel a difference in temperature (although we are already sensitive to temperature changes of 1˚C). It ran for four years straight until a power surge killed the system (killed the PSU and fried the motherboard somewhere near the memory sockets). I transferred the CPU to another computer and it lasted for three more years before finally giving out after moving the computer to a new home. I still have the CPU and the Shuttle casing somewhere around as I've grown quite fond of the pair.
Although I wouldn't worry too much about the high temperatures. Yes, 100˚C sounds high, but remember this is only a very local measurement at the actual cores of the CPU. In a tightly-packed Macbook Pro the CPU cores quickly reach ~98˚C, but the CPU proximity remains at about 55˚C (about 20˚C increase compared to idle; this number is roughly equivalent to heat sink / CPU casing temperatures reported by most desktops). What about the SSD and batteries in the Macbook? They increase with only 1˚C to 28˚C. It's like lighting a cigarette lighter in a room. The flame is hot, but the rest of the room in not melting away.
Regarding all these worries about high temperatures. I'm not an electrical engineer, but my guess for all these worries is that back in the old days with electrolyte capacitors high temperatures (say >65˚C) would drastically reduce the lifespan of your system as it could potentially cause the capacitors to rupture due to increased pressure caused by the liquids. However, with miniaturisation of electronic components came the solid-state capacitors that no longer use liquids that can come to a boil at high temperatures. Consequently, these capacitor have been rated at a safe operating temperature of up to 125˚C. Safe operating temperatures defined by Intel are guaranteed by throttling the CPU.
P.S. I'm not saying temperature does not have an effect of life span of electronics, but I don't think the impact is as significant as it used to be. I love to let machines crunch numbers and process data, and I've had many machines operate at high temperatures. The best memory is of a small form-factor Shuttle casing with a Pentium D 950 (about 135W if I recall correctly) that would run at >105˚C (back in those days the software tool would only show graphs going as high as 100˚C). It was packed in a small wooden cupboard, and when you got close you could actually feel a difference in temperature (although we are already sensitive to temperature changes of 1˚C). It ran for four years straight until a power surge killed the system (killed the PSU and fried the motherboard somewhere near the memory sockets). I transferred the CPU to another computer and it lasted for three more years before finally giving out after moving the computer to a new home. I still have the CPU and the Shuttle casing somewhere around as I've grown quite fond of the pair.
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
Is because you do not read what is written
Ventilation is in the red, with no reserve!
CPU at +/- 95C and is throttling!!!
Oh trust me. I read every word in this thread... Out of morbid curiosity.
Every Mac, ever, does what you are describing under that kind of load.
Is because you do not read what is written
Ventilation is in the red, with no reserve!
CPU at +/- 95C and is throttling!!!
No point of getting i7 if it throttles to the performance of an i5 or worse than i5 if i5 runs cooler