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iMac Pro iMAC Pro gets warm when in sleep mode!??

caoc9

caoc9

macrumors newbie
Original poster
Feb 20, 2018
12
0
Hi

I have recently bought a iMac Pro base-model. It work like a charm and stays very cold when I use it. However when I leave it, and it eventually goes in sleep mode it slowly warms up (It feels warm to the hand when touching low on the back, not burning but noticeable) to the point where the fans (and they are never noticeable when I use the iMac) starts running at full blast for about 10-15 sec then shuts off. How often that happens when it is in sleep mode is different. But normally if I leave the iMac in sleep mode for about 20min or more and wakes it up, it always starts out with 10-15sec of full blast on the fans that it cools down and stays cold when I use it.

I installed the iMac from a timemachine backup (came from a normal iMac) But I have tried a fresh install on a different partition.

Has anybody experienced this, and did they solve it? I have talked with apple support and when through "all" possible software things that can be done. Reset Varm etc. create new user, create new partition with a fresh install. My next step is to hand it over to a repair shop, but before I do that I would like to hear if others have had a similar issue... For sure it should not start heating up in sleep mode and then run totally cool during normal use.....

Thanks for you inputs...

Regards

Per
 
If the iMacP runs cooler "when running" then when sleeping, I'd suggest you try this (for 3-4 days):

1. Go to energy saver pref pane
2. Set sleep to "never" (that's right)
3. Set "display sleep" to whatever interval you want
4. Just leave it that way.

I doubt there's much of an energy difference between "running at idle" (with the display off) and sleeping with these, anyway.

Next time you catch it "sleeping" with the fan running, immediately open Activity Monitor and see what processes are running.

Sounds like something's going on "behind the scenes" that's eating up CPU power.
It could be a "background process" and not any particular application.
 
Thanks for the suggestions. I will try both. But it does not change that this should not be necessary!??

I would be interested in knowing if others with iMac Pro have experienced this behaviour.

Thanks

Per
 
I haven't had this behaviour with my iMac Pro. I don't use Power Nap or FireVault. Don't know if that matters, but just in case..
 
Thanks Mac32, I will try it and report back.

Per
 
So, a quick feedback on your suggestions. Turning off Power Nap while the sleep mode is on, does not work, it still heats up when it goes to sleep.

Turning off sleep mode all together does works, the screen goes out and the iMac remains ice cold and no noise from the fans.

Obviously that is not the way it should work! I guess I must have a hardware failure since it seems that not many other iMac Pro owners have experienced this.
 
Could it be a software bug connected to Firevault and the T2-chip? Try turning off Firevault? Just guessing here. If you still have this issue after this, then I'm out of ideas. What kind of configuration do you have?
 
Firevault is already off....
Standard base model. 3,2ghz, 32Gb RAM, 1Tb HD.
 
WilliamG I am listening! What would you suggest.

I have made a new partition with a fresh instal, same issue.

I have currently turned off sleep and now the issue is gone. If I put it in manual sleep the issue comes back.

Regards
Per
 
I know several other iMac Pro users reported on this issue late December/early January. Have you checked previous threads, in case a solution was offered?
 
I remember mine did this a few times in the first week I had it. I thing it might have been spotligt indexing or some system stuff running when I didn't us the iMac Pro.
 
Mac32, I did see it buried in one thread, unfortunately the guy did not report back of the outcome... Other than that I have not come across the issue..

Nordicappeal, I did send a data dump to the Apple engineers and they could not find any reasons why it heated up in sleep mode...
 
OP wrote:
"Turning off sleep mode all together does works, the screen goes out and the iMac remains ice cold and no noise from the fans.
Obviously that is not the way it should work! I guess I must have a hardware failure since it seems that not many other iMac Pro owners have experienced this."

A bit of the ol' Fishrrman's advice:
Use what works for you.
Ignore what doesn't.

You can keep banging your head against the wall, trying to discover why it overheats in sleep mode.
Or... you can follow my suggestion in reply 2 above, and have it run cool.

Which one of these choices.... "works".......?
 
caoc9 said:
WilliamG I am listening! What would you suggest.

I have made a new partition with a fresh instal, same issue.

I have currently turned off sleep and now the issue is gone. If I put it in manual sleep the issue comes back.

Regards
Per
Click to expand...

Is it possible that since the iMac Pro is much more powerful, that sleep mode warms it up that much more due to no fans running? When the iMac is fully on the fans ALWAYS run, keeping it cool. But not in sleep mode so every now and then it just has to cool off?

I would not be surprised if this is the situation. If you have a Kill-A-Watt meter, you can check the power draw powered on (display off) and in sleep mode.
 
caoc9 said:
WilliamG I am listening! What would you suggest.

I have made a new partition with a fresh instal, same issue.

I have currently turned off sleep and now the issue is gone. If I put it in manual sleep the issue comes back.

Regards
Per
Click to expand...

Hello,

as early adopter, I've had same issues with my iMac Pro. Many weird kernel crashes, warm/noise in sleep mode...
Extensive memory tests were ok, Apple HW test too... very strange.

What helps me?
I've installed 10.13.4 beta on separate partition ... there was apparently a firmware update.
Did PRAM/SMC reset after update. No issues in 10.13.3 since update. 18 days uptime now.

Good luck.
 
xyzy, Thanks for that info. That should be relatively easy to test. Did you do a fresh install on 10.13.4 or did you do 10.13.3 and then updated afterwards? If you did not update, how did you make a fresh install with the beta version?

Thanks for sharing!

Regards

Per
 
caoc9 said:
xyzy, Thanks for that info. That should be relatively easy to test. Did you do a fresh install on 10.13.4 or did you do 10.13.3 and then updated afterwards? If you did not update, how did you make a fresh install with the beta version?

Thanks for sharing!

Regards

Per
Click to expand...

1. in Disk Utility create new secondary APFS partition (not APFS volume) on internal SSD
2. boot to recovery setup (Cmd+R), install 10.13.3 on new partition
3. update secondary system to 10.13.4 (developer or public beta)
 
If you have an alternate user account setup run the iMP under that account to see if the issue still arises. If no alternate user account, then suggest you configure one and test under that user account. This should at least indicate if the issue is somehow related to a specific user account's configuration and/or setup etc.

What you describe should not be happening. I have iMP, 10-core, 1TB SSD, 128GB RAM, Vega 64 and this issue has never arisen. The only time I've hear the fans (and when I do the noise level is very low) is when I've performed a macOS upgrade.

Under just about all normal use of the iMP the fans should never rise much above 1500 RPM.
 
xyzy. I have tried your suggestion at it does not work 100% but I do sense a less heating up than with my normal profile that are on 10.13.3. But the fact that it the heating up during sleep is less outspoken still indicates a software issue!??

bxs, Thank you very much for your experience. This is my exact expectation, and heating up in sleep mode should not happen.

I do understand that the functionality of the machine is not effected and I do have a workaround (don't use sleep). But fundamentally I have a problem of spending this much money and knowing that it has a fault. Furthermore what might be the long term impact?

Thanks for all you suggestions and experience

Regards

Per
 
caoc9 said:
xyzy. I have tried your suggestion at it does not work 100% but I do sense a less heating up than with my normal profile that are on 10.13.3. But the fact that it the heating up during sleep is less outspoken still indicates a software issue!??

bxs, Thank you very much for your experience. This is my exact expectation, and heating up in sleep mode should not happen.

I do understand that the functionality of the machine is not effected and I do have a workaround (don't use sleep). But fundamentally I have a problem of spending this much money and knowing that it has a fault. Furthermore what might be the long term impact?

Thanks for all you suggestions and experience

Regards

Per
Click to expand...

It has not been established that this is even an issue. My 2014 5K iMac I’m pretty sure runs warm in sleep mode. But since I leave it on with a hot corner for display off, it’s not an issue.
 
I have now checked the power draw of the iMac in normal idle, idle with screen off and in sleep mode. In normal idle it uses about 100W, idle with the screen off 60-70w and in sleep mode it is about the same as idle screen off, 60-70w. It is still heating up in sleep mode, but the power usage could suggest that it is not entering real sleep mod except that the fans are no longer cooling wherefore it is heating up.... maybe!?!

I would be very interested in hearing others power use in sleep mode!

Regards

Per
 
A new OSX update must be right around the corner. Wait and see if the update fixes your issue. If not, try reinstalling the OSX (and see if the issue persists with a clean install without migrating any old files). If that doesn't help, I would return the iMac Pro - but not until I'd tried those first things. If not, you might just be getting into a lot of hassle for nothing (ie. returning the iMac Pro for a new item with the same issue). If there is a defect, surely Apple will gladly get everything sorted out. I do have my criticisms of Apple now and then, but their customer service has always been excellent in my experience.
 
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Actually there have been quite a few reports of this issue. I am one of the first people that reported this on the forum. I can tell you that swapping the machine will yield the same results. Been there and done that. No change. I have worked with a senior tech and engineering at Apple and they feel that there is a process that is running in Icloud causing the issue. You can confirm that the machine isn't the root cause of the issue by creating a test account in system preferences under users. Login as the test user and make sure the sleep settings are the same as your normal user account. Let the machine go to sleep overnight or when ever convenient. You will find that the machine doesn't overheat to the point of where the fans kick in high mode waking the computer. Reinstalling the operating system will not resolve the issue. I would definitely call Apple as well and get a senior tech involved. Once they have enough reports one would think the issue would be addressed in a future OS X update. Let us know the results with test user.
 
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