# imac 27" fans when in full screen



## Bernard Smith (Dec 21, 2017)

Operating System:
Exact Lightroom Version (Help menu > System Info):
why do the fans on my 2017 27" imac 5k cut in every time I view in full screen when in develop mode...


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## Dave Miller (Dec 22, 2017)

Mine does too. 

I assume it's because the processes are working hard and heating the processors; hence the need to cool them.


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## stevevp (Dec 22, 2017)

As I am about to purchase a 2017 iMac (i7 4.2GHz), how annoying is the noise?


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## Dave Miller (Dec 22, 2017)

stevevp said:


> As I am about to purchase a 2017 iMac (i7 4.2GHz), how annoying is the noise?



It's hardly audible, I can only hear mine if the room is quiet and I know what to listen for.


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## stevevp (Dec 22, 2017)

Good news, many thanks for the advice.


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## clee01l (Dec 22, 2017)

Thanks for the information.  I was not even aware that my 5K iMac had a fan.  If it runs, I can't hear it (and yes I do have hearing aids!).

Periodically vacuum the exhaust ports of the iMac for better cooling. You can also get a thermometer app to monitor the temperature, if you are concerned about over heating.


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## Gnits (Dec 23, 2017)

Some people will not notice..... some people will be annoyed .... some people will wonder where the noise is coming from. I have heard the fan while previews were been built after import. Brand new iMac , I7 with 64Gb.


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## Jim Wilde (Dec 23, 2017)

Bit of a no-win situation for Adobe....some users complain that LR doesn't use enough of the system resources, so they've tried to address some of that with increased use of parallelism in LR Classic, which as a result means the system works harder, which causes the CPU temperature to rise, which in turn causes the fan to be used to keep it cool, which can lead to complaints that LR is causing their system to overheat.


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## Gnits (Dec 23, 2017)

I would not blame Adobe on this one.  I would want max performance my processor can deliver.


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## Jim Wilde (Dec 23, 2017)

I agree with you, but unfortunately not everyone sees things the same way.


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## Ian Hutchinson (Dec 23, 2017)

I use an app called Macs Fan Control to run the fans in both my iMac and Macbook pro, it has the advantage of telling you which fans are working the most.
Macs Fan Control Download for macOS & Windows (Boot Camp)


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## stevevp (Jan 11, 2018)

I took delivery of my new iMac a couple of days ago -  27” i7 4.2GHz 1TB SSD, 8GB Radeon Pro Graphic card and 8GB RAM (pending an additional 32GB which I will fit myself). It’s my first iMac which I’m still getting to grips with, but I’ve been immediately struck by the fan noise even when LR is just syncing images in the background and the fan just cycles off and on. Not ideal and I’ll see how it goes. I presume having only the current minimal 8GB RAM is not a factor?


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## Gnits (Jan 11, 2018)

I notice it for batch intensive activity, such as import phase where previews are been built or export when processing a number of files.


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## Bernard Smith (Jan 11, 2018)

stevevp said:


> I took delivery of my new iMac a couple of days ago -  27” i7 4.2GHz 1TB SSD, 8GB Radeon Pro Graphic card and 8GB RAM (pending an additional 32GB which I will fit myself). It’s my first iMac which I’m still getting to grips with, but I’ve been immediately struck by the fan noise even when LR is just syncing images in the background and the fan just cycles off and on. Not ideal and I’ll see how it goes. I presume having only the current minimal 8GB RAM is not a factor?


I have exactly the same spec as you but only upped the ram to 24Gb..  mine only ever uses the fan when in develop mode...I guess that it's just a heavier load that causes the temperature to rise and I actually am glad that the fan kicks in.....only does it in warmer weather here in Melbourne...  so the cooler the room temperature the better everything is.


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## Bernard Smith (Jan 11, 2018)

Bernard Smith said:


> I have exactly the same spec as you but only upped the ram to 24Gb..  mine only ever uses the fan when in develop mode...I guess that it's just a heavier load that causes the temperature to rise and I actually am glad that the fan kicks in.....only does it in warmer weather here in Melbourne...  so the cooler the room temperature the better everything is.


It looks like the price we pay for Adobe getting LR to work at a reasonable speed is to use more of the system and therefore increase the load and consequently the temperature.... can't have it both ways..


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## stevevp (Jan 11, 2018)

Might have to get ear plugs! 
Any thought on the minimal RAM being a factor?


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## stevevp (Jan 14, 2018)

Bernard Smith said:


> It looks like the price we pay for Adobe getting LR to work at a reasonable speed is to use more of the system and therefore increase the load and consequently the temperature.... can't have it both ways..


Unfortunately after a couple of days of Lightroom use, I'm not seeing much in the way of reasonable speed. The new iMac is bogging down as much as the old PC did and I'm having to do reboots as before. I'll get the additional RAM ordered and see where we go ...


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## clee01l (Jan 14, 2018)

stevevp said:


> Unfortunately after a couple of days of Lightroom use, I'm not seeing much in the way of reasonable speed. The new iMac is bogging down as much as the old PC did and I'm having to do reboots as before. I'll get the additional RAM ordered and see where we go ...


Perhaps your issue is this: 


stevevp said:


> I presume having only the current minimal 8GB RAM is not a factor?


  I have a late 2015 iMac with 3.2 GHz Intel Core i5 and 32GB of RAM.  I don't have fan noise and I routinely process 36mp RAW files without any of the issues that you seem to have.  Are you running any 3rd party Malware apps that sit in between the OS and LR?  You do not really need resident Malware apps on a Mac.


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## stevevp (Jan 14, 2018)

Hmmm. I wouldn't even begin to know how to check for malware on a (brand new) Mac - I ran Windows Defender on the old PC. Do you run anti-virus software on yours?


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## clee01l (Jan 14, 2018)

stevevp said:


> Hmmm. I wouldn't even begin to know how to check for malware on a (brand new) Mac - I ran Windows Defender on the old PC. Do you run anti-virus software on yours?


You would know if you installed an anti virus app like McAfee or similar.   Windows Defender is Microsofts own Malware app. and Microsoft has finally gotten the message and Windows Defender will now do the job that used to require other apps like McAfee. 
Apple OTOH, is diligent in quickly patching the OS as soon as vulnerabilities are discovered.  That does not mean that you are entirely safe.  For me it means that I do not need antivirus software sitting between my app(LR) and the OS.  I do run a non resident app called MalwareBytes every month or so.  Usually when it runs if finds adware that it cleans up.


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## stevevp (Jan 14, 2018)

Many thanks for the advice. MalwareBytes has come back with a clean result. Do you uninstall it after each use?


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## clee01l (Jan 14, 2018)

stevevp said:


> Many thanks for the advice. MalwareBytes has come back with a clean result. Do you uninstall it after each use?


No, MalwareBytes is not a resident program like McAfee or Avast.  You start the app like any other app and click to run a full scan.  When you are done, you click {Quit}  like you would with LR , Pages or any other app.


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## stevevp (Jan 14, 2018)

My download has a Premium trial for a month which seems to leave Malwarebytes Agent running in the background. I guess I can kill it?


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## clee01l (Jan 15, 2018)

stevevp said:


> My download has a Premium trial for a month which seems to leave Malwarebytes Agent running in the background. I guess I can kill it?


You don't need the trial.  You only need the free version.  Also I forgot to mention there is another product (not free) that I also run occasionally for an anti virus check called BitDefender for Mac.


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## stevevp (Jan 15, 2018)

Unfortunately, I clicked on the free trial button and that's what I ended up with. I found you can turn off the Real Time Protection but it remains visible in Activity Monitor. I might just uninstall it for now and reinstall in a few months for another check. Many thanks again for your advice.


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## Bernard Smith (Dec 21, 2017)

Operating System:
Exact Lightroom Version (Help menu > System Info):
why do the fans on my 2017 27" imac 5k cut in every time I view in full screen when in develop mode...


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## CameraCarl (Apr 7, 2018)

stevevp said:


> I took delivery of my new iMac a couple of days ago -  27” i7 4.2GHz 1TB SSD, 8GB Radeon Pro Graphic card and 8GB RAM (pending an additional 32GB which I will fit myself). It’s my first iMac which I’m still getting to grips with, but I’ve been immediately struck by the fan noise even when LR is just syncing images in the background and the fan just cycles off and on. Not ideal and I’ll see how it goes. I presume having only the current minimal 8GB RAM is not a factor?


I am writing to ask how satisfied you are with your iMac after a few months of use.  I just received a new iMac similar to yours from Apple as a replacement for a 2015 iMac which was not able to be repaired, and I, too found lots of fan noise.   I'm still within the US Apple Store's 14 day return period and am trying to decide whether to keep it or return it.  So your thoughts are appreciated.


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## stevevp (Apr 7, 2018)

I continue to have mixed views on my iMac. The noise is still very annoying. It's particularly noticeable coming, as I did, from a tower PC with a sound-proofed "quiet" case under my desk to an iMac with fan noise right in front of my face. Fitting the additional 32GB of RAM made no difference. Performance in Lightroom is extremely erratic. Some days it bogs down to the extent that it's unusable. Other days it runs fine.

The decision on returning the i7 is tough. I frequently regret not returning my iMac for an i5 but convince myself that I have a better machine. On balance I probably wish I had.  I just hope that Adobe, in an effort to make LR run faster, improve the coding which might just make the iMac run a bit quieter.

There's a long thread here 2017 iMac: i7-7700K hot & loud, i5-7600 cool & quiet: Mac Talk Forum: Digital Photography Review if you haven't seen it and wish to be confused further! I'll be interested in what you decide. Good luck.


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## CameraCarl (Apr 7, 2018)

I'm sorry to hear that adding RAM does not help. Thanks  for taking the time to give me an update.


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