My iMac keeps going to sleep while I'm working.

[RVC1]

This has been happening almost since I purchased the computer however it's continued to get worse with each passing month. Especially when working in Photoshop (especially the lasso tool), my iMac will just go to sleep on it's own. Even more so when something is streaming in the background. I believe it is overheating. Is this a feature of the system? To force sleep when it's too hot? I almost can't work anymore. And I think my computer's specs are good enough to carry the tasks at hand, this shouldn't be a problem, yet it is. What accompanies this forced sleep mode is my fan spinning fast and loud right before it. My fan does this all the time actually, but mostly when in some apps.


I vowed not to get another iMac because of the poor design but I did anyway, hoping the issues I had with my previous model were isolated. They weren't. If this is something common can I please have some advice on how to fix this? I downloaded an app called Macs Fan Control to see if I can record the internal temperatures. Not sure if these are high but in case this helps:


4 cores are usually around 80c and sometimes between 90 and 100c.

GPU Diode goes up to over 100c at times, even over 110c.

I suspect the numbers would go higher if my computer didn't just shut down (sleep).


Am I off base? Is it something else?


Some details:

• iMac (Retina 5K, 27-inch, Late 2014)

• Processor: 4 GHz Intel Core i7

• Memory: 32 GB 1600 MHz DDR3

• Graphics: AMD Radeon R9 M295X 4096 MB

• OS: 10.14.3

• I have an additional display connected: 27" Thunderbolt


I have my apps on an internal SSD and all my work files on an external drive.


I use Photoshop with Chrome open in the background as well as Outlook and maybe iTunes. Some other light apps are open at times too. Nothing too crazy, I don't think. The problem does get better if I shut down apps and restart. But it's not long before it happens again.


I tried resetting the SMC and NVRAM a while back but that did nothing.


PLEASE HELP! What do I do?

Thank you.

 

[chscag]

If your iMac were overheating it would probably shut down or reboot. It is possible that it might also sleep. The temps you posted are a bit high but may be because of the strain you're putting on the GPU during Photoshop and the fact that you have a TB display attached.

How about if you run the iMac without the TB display and the G-Raid, does the same thing happen? Also, have you tried running in Safe mode for awhile?

I just thought about something else.... have you checked all your fans for speed? I believe your model iMac has three fans but am not sure about if it is still on that model. I know my 5K iMac 2017 model 27" Retina only has one fan.