BBBD discussion with Conrad Chavez

[L Robbin]

Lightroom Version

LR 12.4

Operating System

1. macOS 13 Ventura

Conrad wrote the following below last April And only now am I getting to it (sorry!). I want to ask about this comment:

If you are experiencing a slowdown, keep Activity Monitor open and specifically look first at two of the tabs: CPU (sorted by % CPU, in descending order), and Memory (sorted by Memory column, in descending order).
Got it.

With those sort orders, the applications and other processes using the most CPU or memory at that moment will be at the top of the lists. You can control how often it checks by choosing View > Update Frequency.

Use that info together with the displays at the bottom of the Activity Monitor window. At the bottom of the CPU tab, if there is a significant percentage of Idle CPU usage, then the Mac is not completely busy and it almost doesn’t matter what the listing above says because there is still spare power. If that is what it looks like during a slowdown, then maybe CPU usage is not the problem. But, if Idle is close to 0% and the graph is full, then you do want to look in the list and see which applications are hogging your processor. For an application to really slow things down, its CPU usage will be well over 100% (macOS measures 100% per core, so a fully used CPU on a 4-core Mac would show close to 400% CPU usage.)
I'm not sure about this. I have included two captures of the Activity Monitor displaying CPU. (BTW recently , the issue has been I take an action in LR and 5-10 seconds and then LR responds) What do you see when you look at these? Because I'm not sure

Similarly, at the bottom of the Memory tab, if Memory Pressure is green, then the numbers in the list above don’t mean much because the overall memory load on the Mac is still very low and not a problem. However, if you see Memory Pressure stay in the orange or red zones (full graph) for a long time, then the Mac definitely doesn’t have enough memory for what it’s doing, and it might help to quit some applications or close some browser tabs.

I've included another display this time of Memory.

If both CPU and Memory look great when you have a slowdown, then the bottleneck could be something else; the next areas to look at might be graphics hardware or storage speed.

Also, what kind of Mac hardware are you using? In general, the older Intel-based Macs may struggle more with the advanced features in today’s photo software, with more lags and more heat and fan noise. The newer Apple Silicon Macs are a lot more efficient, and mine (a base model M1 Pro MacBook Pro, 32GB memory) seems to crank through all kinds of work without complaining much. There are times when I have multiple applications open for layout (InDesign, Photoshop, Lightroom Classic), and other times when I run multiple applications for video editing (Premiere Pro, After Effects, Photoshop), and it all seems to run just great with Mail and Safari also up in the background.
I have an M1 iMac.

The last thing I can think of doing to reduce slow down time and the BBBD is switching from Opera to Safari.

 

[L Robbin]

OOps! Here are the captures for above.

 

[Conrad Chavez]

Well, let’s see…You have an M1 iMac, which has 8 cores, and macOS reports 100% for each core, so the first screen shot showing Lightroom Classic using 102.2% CPU means it’s using roughly 1/8 or only 13% of total CPU capacity. So the CPU is not completely busy. In the second screen shot, Lightroom Classic has dropped to 10.8% (1% of total CPU capacity), using less than macOS WindowServer (a routine background operation). So there’s no obvious smoking gun in the CPU department. Unless it’s a short spike; to catch that you might have to decrease the Activity Monitor reporting interval (View > Update Frequency).

The Memory tab shows Memory Pressure as green; at times it’s around 50% which threatens to go yellow, but it never does. So memory seems to be coping with everything well enough. Opera Helper (GPU) is using around half a gigabyte, maybe the slowdown is due to contention between that and something Lightroom Classic is doing with the GPU at the same time? I don’t have the technical background to know that…but you might get some info by, as you said, seeing if it makes any difference to use Safari instead.

One other detective approach is to open Console and watch for errors during the lag. For example, if there were lots of I/O errors during a lag, that would indicate a problem with storage. But chances are an obvious clue might not appear from that approach.

So, it is puzzling as to where the slowdown is coming from…Other people seem to be reporting similar Lightroom Classic lags on even more powerful Apple Silicon Macs, but not everyone, and there don’t seem to be obvious solutions (yet).

 

[L Robbin]

OK, I'll investigate some more. Also switch to safari with few tabs on. See what happens. Thanks.