27 Replies Latest reply on May 3, 2018 4:12 PM by johnrellis

    iMac 2017 fan noise

    Arctic Sounds Level 1

      Hi all,

       

      I've just bought a new 2017 iMac with a Retina 5K 27" display. It has a 4,2 GHz i7 processor and 8 GB RAM. When I'm running Lightroom Classic CC 7.2, the fan of the iMac blows very loud. No clicking noise, but just loud blowing, impossible to ignore. Mostly or maybe only when I'm in the Develop mode, and only with Lightroom. I didn't have this issue with my other iMac which was aprox. 8 years older. Does anyone have the same problem and does anyone know what's causing this problem? Is there a fix? Would upgrading my RAM solve anything?

       

      Thanks in advance!

        • 1. Re: iMac 2017 fan noise
          Arctic Sounds Level 1

          Nobody else has this problem? It's driving me nuts...

          • 2. Re: iMac 2017 fan noise
            Just Shoot Me Adobe Community Professional

            The thermal design of the newer iMac is bad. To thin a case, not enough air flow, equals fans spinning at MAX RPM to Try, I say TRY, and keep it cooled down.

            1 person found this helpful
            • 3. Re: iMac 2017 fan noise
              johnrellis Most Valuable Participant

              Most apps use only a tiny fraction of your processor's capacity. A frequent complaint about LR is that it is too slow, so Adobe has worked hard to have LR use as much of the CPU and graphics processor as possible. That consumes a lot more power, which generates a lot more heat, which requires fans to dissipate. That is all by design. Complaints about excessive fan noise should be directed to Apple.

               

              LR may be running some background activities increasing the CPU load:

               

              - It may be building a lot of previews (especially if you've just moved to a new computer).  This can take a long time for large catalogs.

               

              - If you have Sync with the LR CC enabled, LR 7.2 introduced a new background activity that computes a  one-time hash for every synced photo. This can take a while if you have lots of photos synced, but once it's done, you shouldn't notice it again.  You can either wait overnight for it to complete or disable sync and restart LR.

               

              - Face detection may be running.

               

              You can see which of these background activities (previews, sync, face detection) is running by clicking on the nameplate in the upper-left corner:

              Finally, there have be a few intermittent reports of LR consuming a lot of CPU when supposedly no foreground or background activities are occurring. You can check that by running Activity Monitor.  When doing absolutely nothing, LR should consume no more than 5-10% CPU.

              3 people found this helpful
              • 4. Re: iMac 2017 fan noise
                Looty81 Level 1

                What do you mean by "one time hash"?

                • 5. Re: iMac 2017 fan noise
                  Looty81 Level 1

                  I just got a new 27 inch iMac and love it. However, I don't hear the fan sound you're speaking of. Although, I have the 3.4 i5. Instead of their fusion drive, I customized it to order with the 1TB SSD. The machine runs fine as is, but I'll be upgrading the RAM soon. I just didn't want to pay the Apple premium to do so, obviously.

                  • 7. Re: iMac 2017 fan noise
                    Just Shoot Me Adobe Community Professional

                    Looty81  wrote

                     

                    I just got a new 27 inch iMac and love it. However, I don't hear the fan sound you're speaking of. Although, I have the 3.4 i5. Instead of their fusion drive, I customized it to order with the 1TB SSD. The machine runs fine as is, but I'll be upgrading the RAM soon. I just didn't want to pay the Apple premium to do so, obviously.

                    Not to derail this discussion but are you sure YOU can upgrade the RAM. I thought all new iMac computers were sealed. No removable panel to get at anything inside of them.

                    • 8. Re: iMac 2017 fan noise
                      Looty81 Level 1

                      You can't upgrade the 21.5's, but you can upgrade the 27's. :-)

                       

                      https://9to5mac.com/2017/06/21/how-to-upgrade-ram-2017-5k-imac-video/

                      • 9. Re: iMac 2017 fan noise
                        edmondl42655864 Level 1

                        I also got my 4.2 GHz i7 processor and 40GB RAM. When using Lightroom Classic, the fan kicks in whenever I am dealing with RAW files, either browsing or editing. It will quiet down again but then will engage on and off again. Jpeg files have no such issues. Also, when watching 8K videos on YouTube, the fan will be in full blast without stopping until the video is finished. Yes, annoying.

                        • 10. Re: iMac 2017 fan noise
                          Looty81 Level 1

                          Very interesting. I wonder if it's something with the i7's and the configuration as I don't experience this with my 3.4GHz i5 with 8 gigs of ram. Eventually I'll be upgrading the ram, but haven't yet. I'm also running a 1TB SSD.

                          • 11. Re: iMac 2017 fan noise
                            Arctic Sounds Level 1

                            Thanks for all your replies. I guess it will have something to do with i7 processor or maybe just something in the configuration of the fans. Definitely not a complaint to Lightroom. I hope Apple will be able to fix this soon with a software update, because it's not much fun working at a machine which makes this much noise...

                            • 12. Re: iMac 2017 fan noise
                              nunoferreira Level 1

                              Same problem here. I also have a late 2017 iMac with an i7 4.2GHZ, top of the line graphic card and 40 GB of RAM, and the fans will kick at full speed every time I'm working in LR, even with 1:1 previews and smart previews built beforehand. Strangely, that issue disappeared with LR 7.2 to return in 7.3. So, I believe it's an Adobe problem and not a heat issue with the iMac. That doesn't happen with any other software.

                              1 person found this helpful
                              • 13. Re: iMac 2017 fan noise
                                johnrellis Most Valuable Participant

                                I believe it's an Adobe problem and not a heat issue with the iMac. That doesn't happen with any other software.

                                Most apps use only a small fraction of the CPU and almost none use the full capabilities of the graphics processor (GPU).  Thus, it's not surprising that many observe LR starting up the fans but not other apps.

                                 

                                There have be a few intermittent reports of LR consuming a lot of CPU when supposedly no foreground or background activities are occurring. After verifying that LR isn't running any background tasks, run Activity Monitor.  When doing absolutely nothing, LR should consume no more than 5-10% CPU.

                                • 14. Re: iMac 2017 fan noise
                                  samueld79715609

                                  I noticed the same thing with my iMac 27 5K i/ 4.2 GHz. Also it seems like the performance i develop mode got worse after updating to 7.3.. Very frustrated as it doesn't happened in photoshop even tho I'm editing huge multiple files.

                                  • 15. Re: iMac 2017 fan noise
                                    Chris Tsorotes Level 1

                                    Roll it back to Version 7.0.

                                     

                                    It runs like a pig on the latest Mac's.

                                    • 16. Re: iMac 2017 fan noise
                                      Arctic Sounds Level 1

                                      Do you mean it is better in 7.0?

                                      • 17. Re: iMac 2017 fan noise
                                        nunoferreira Level 1

                                        johnrellis Screen Shot 2018-04-26 at 14.49.07.jpg

                                         

                                        My Lr is always at 125% of the CPU speed as you can see in the attached screenshot, which I find very strange. How can a software use 25% more CPU power than it's own processing capacity? All background tasks are paused, as usual. One thing is for sure. Lr is much slower especially in Develop mode and the fans are kicking at full speed since the update to version 7.3.

                                        • 18. Re: iMac 2017 fan noise
                                          johnrellis Most Valuable Participant

                                          My Lr is always at 125% of the CPU speed as you can see in the attached screenshot,

                                          Double-check that Sync and face detection aren't running in background. LR 7.2 and 7.3 introduced changes that can cause them to run for a long time.

                                           

                                          Both Mac and Windows have the convention in their detailed process listings that "100%" means 100% of one virtual processor. So if your computer has 4 physical cores and two "threads" per core (in Intel's lingo), there is a total of 8 virtual processors, and thus a process could use up to 800% of a CPU (if it's using all 8 virtual processors, which LR can do).

                                           

                                          But in the summary at the bottom of Activity Monitor, the three percentages System, User, and Idle are expressed with a maximum of 100%, where 100% means all virtual processors are being used.  If just one virtual processor is being used, that summary will show just 12.5% total.  Confusing?

                                          1 person found this helpful
                                          • 19. Re: iMac 2017 fan noise
                                            nunoferreira Level 1

                                            I have always Sync, Face Detection and Address Lookup paused, so no issue there. I understand what you mean with the CPU percentage, so yes, that's very logical that Lr uses 125%. I simply didn't relate to the number of virtual processors but now I know it can reach higher percentage values.

                                             

                                            I just tried to move the exposure slider and the CPU percentage went up to 605% and the fans just fired up at full speed. That's what I think it's not normal and it was an issue that I've only had in version 7.0, 7.1 and now in 7.3. Version 7.2 was the only one that seemed to fix the issues, the one where Intel helped Adobe.

                                             

                                            Screen Shot 2018-04-26 at 16.05.22.jpg

                                            • 20. Re: iMac 2017 fan noise
                                              johnrellis Most Valuable Participant

                                              I just tried to move the exposure slider and the CPU percentage went up to 605% and the fans just fired up at full speed.

                                              I observe the same behavior on my MacBook Pro with a Retina display.  Here's the total CPU usage resulting from moving the exposure slider back and forth for about 5 seconds:

                                              But I think this CPU usage is by design and desirable.  The number one complaint about LR and Camera Raw over the years has been that it is too slow. Adobe has worked hard in the last couple of years to make it faster, by using more of the available processors and the GPU (using the GPU effectively can require using more of the processors).   Camera Raw's non-destructive editing model, especially with all the newer adjustments Adobe has added in the later process versions, is much more CPU-intensive than the simpler pixel-editing model of Photoshop et al.   (Adobe has also increased the use of processors for Library and export activities as well.)

                                               

                                              Very few apps stretch the CPU in this way, and the compute power of our computers far exceeds the needs of most of our apps. That's why people are surprised to hear the fans turn on when they run LR, and naturally they assume something is wrong. 

                                              • 21. Re: iMac 2017 fan noise
                                                johnrellis Most Valuable Participant

                                                Also, note that GPUs consume a lot of power -- they've got a huge number of transistors!  So LR using 500% of the CPU and the GPU is generating a lot more heat than a workload using 500% CPU and no GPU.

                                                • 22. Re: iMac 2017 fan noise
                                                  nunoferreira Level 1

                                                  I understand that Lr needs a lot of processing power and that produces more heat because of all the transistors of the CPU and GPU, especially on the retina iMac and Macbook Pro and that Adobe spent the last years trying to make it faster and addressing all the user concerns. But if the latest Apple computers use even more powerful graphics cards, more powerful processors and faster RAM, shouldn't Lr be faster and use all that power to run smoothly? How come a lower spec 2015 retina iMac runs faster and without issues than a late 2017 top of the line iMac with 64GB of faster RAM? And how did all those issues disappear in version 7.2 to reappear in version 7.3?

                                                  • 23. Re: iMac 2017 fan noise
                                                    Todd Shaner Adobe Community Professional & MVP

                                                    The i7 4.2 GHz Kaby Lake processor used in the iMac has a maximum Thermal Design Power (TDP) of 91 Watts. Imagine squeezing a 100 Watt conventional tungsten light bulb inside the thin iMac enclosure and keep it cool. Having said that it appears some units may have incorrect control settings and/or assembly defects in the heatsink cooling assembly.Some suggestions here:

                                                     

                                                    Constant fan noise on 2017 iMac even at r… - Apple Community

                                                     

                                                    New MBP2017 15" / Fans going crazy when browsing photos

                                                    • 24. Re: iMac 2017 fan noise
                                                      nunoferreira Level 1

                                                      Thank you for the links, trshaner. Yes, from what I saw in other forum threads and speaking with other photographers, it's a well-known issue with the i7 4.2 Kaby Lake processor used in the iMac. I believe something was not well designed by the Apple team to ensure the heat was dissipated correctly.

                                                      • 25. Re: iMac 2017 fan noise
                                                        johnrellis Most Valuable Participant

                                                        But if the latest Apple computers use even more powerful graphics cards, more powerful processors and faster RAM, shouldn't Lr be faster and use all that power to run smoothly? How come a lower spec 2015 retina iMac runs faster and without issues than a late 2017 top of the line iMac with 64GB of faster RAM? And how did all those issues disappear in version 7.2 to reappear in version 7.3?

                                                        From all the reports on the forums for the past few years, Adobe has clearly been struggling with this performance engineering. While on average for most users, they've made significant improvements in performance, especially with the newer 4K and 5K displays, each release brings out some reports of bad performance in the latest version.

                                                         

                                                        Adobe has particularly struggled with higher-end machines (more than 4 physical cores / 8 virtual processors).  As they constantly change and try to improve performance, they encounter (or introduce) new problems. 

                                                         

                                                        Utilizing multiple processors in conjunction with a GPU for interactive image processing requires hard engineering, well beyond the abilities of the average software engineer. Making it more difficult, the GPU manufacturers' drivers can be pretty buggy and only partially hide their variety and complicated performance characteristics from the programmer.

                                                         

                                                        In Silicon Valley, Adobe doesn't have a great reputation for attracting and retaining top engineering talent. I know there are definitely some very talented senior engineers working on LR and Camera Raw, but I think it's pretty clear that overall the quality and depth of the engineering team is limited.

                                                         

                                                        My only suggestion is to keep posting feedback on the official Adobe feedback forum: Lightroom Classic CC | Photoshop Family Customer Community . Product developers read every post there (and infrequently reply) but are rarely seen in this forum.  The feedback there definitely influences Adobe, though the feedback cycle tends to be measured in quarters and years, not days or weeks.

                                                        • 26. Re: iMac 2017 fan noise
                                                          rayo70575913

                                                          Im Having the exact same problem. its pissing me off big time. I spent $4000 on this iMac and its not as good as my 2013 iMac. When I called Apple, they says its Adobe fault, and im sure adobe is saying its apple fault for making a buggy 4.2ghz i7, and us consumers are just being puzzled and ping ponged between apple and adobe. I believe Apple do have a point, because this problem is only happening in LR no other application i'm noticing it. I really hope this gets fixed to at least get our moneys worth.

                                                          • 27. Re: iMac 2017 fan noise
                                                            johnrellis Most Valuable Participant

                                                            this problem is only happening in LR no other application i'm noticing it.

                                                            As explained before, very few applications utilize most of the CPU and GPU, as LR does. So it's not at all surprising that LR causes the fans to come on and other apps don't.  If you don't like that the fans come on frequently when an app uses your computer heavily, complain to Apple.

                                                             

                                                            The very poor LR performance that some experience is a separate issue, and there's no strong evidence that it's related to the amount of CPU usage. For example, my LR performs very well on a MacBook Pro Retina, using the same amount of CPU in Develop as someone with an iMac in which LR performs very poorly: Lightroom Classic CC 7.3 (and 7.3.1) update slowed down my iMac and made fans spin at full speed | Photoshop Family Cust…