Lightroom causes CPU frequenzy to idle around 1 GHZ, slow mac ?????? MBP 2018

[Ricc83]

hello guys, everytime i use Lightroom classic after some time my whole macbook becomes unresponsive, and i see that the cpu frequency hovers around 1ghz, everything is super slow.

once i close lr my mac becomes responsive again....

this is clearly an issue with lr and i reinstalled my mac a few times now...

[johnrellis]

Most likely this is due to clogged or broken fans in the Macbook.  LR uses much more of the CPU and GPU than typical apps (even games), which causes the CPU and GPU to heat up. If the fans aren't working properly, then the CPU will reduce its clock speed until it cools down.

You can try cleaning the fans yourself or take it an authorized repair center.

[Ricc83]

The temperature doesn't seem to be rising though... being at about 56 and I'm in a air conditioned room....

[Ricc83]

If that was true a cpu benchmark like cinebench should have the same effect correct? Let me check...

[johnrellis]

There was a firmware bug with CPU-throttling in 2018 Macbook Pros -- verify that you've updated at least to 10.13.6:

https://9to5mac.com/2018/07/24/apple-releases-2018-macbook-pro-update-to-fix-cpu-throttling-thermal-... 

Other than using a lot of CPU and GPU, there is nothing LR can do to cause the CPU to throttle.  Your screenshot shows sustained CPU utilization above 80%. You can see if LR is indexing faces or building previews (the two most common causes of sustained high utilization) by clicking on the identity plate in the upper-left corner:

[Ricc83]

I'm on the latest macOS and should get firmware updates automatically????

[Ricc83]

So ya that bug should not be the issue. I have litterally just made a few adjustments for 5 min if scrolling and adjusting images in Lightroom. 

i du have to say that I don't hear the fans spinning up really loud at all but they are def spinning.

Lightroom is unbearable to work with after 5-10 min....

[johnrellis]

Did you click the Identity Plate to see if LR was indexing faces or building previews in background?