Logic stalling forever slicing multitrack drums

[mardyk]

I'm not sure when this started. Maybe 4-5 versions back. I like to use flex slicing to quantise multitrack drums. However, I find transient detection with the slicing algorithm less than perfect so I usually do the "slice at transient marker" to cut everything up and adjust the regions to remove errors. This used to take a second or two. Now it takes anything from 20 minutes to several hours of stalling. I've also noticed this when stretching regions in the main window. It got even worse after Apple claimed to have addressed the issue a few versions back.

What's going on here? 

Right now I'm on High Sierra, Logic 10.3.2. quad i7 MBP or Mac Mini. It's been like this since El capitan at least.

[David Nahmani]

One thing to check is your undo history. See if reducing the number of undo steps (Logic Pro X > Preferences > General > Editing) and deleting the undo history (Edit > Delete Undo History) helps?  

[mardyk]

I tried that, it didn't seem to help. I'm thinking it has something to do with flex markers and tempo information.

Right now I have this project with just 14 drum tracks sliced into 1000s of edits, no plugins. The session weighs 645 mb.

Somewhere down the line Logic got really bad at handling lots of edits. I had sessions back in logic 5 with more edits and no lagging. Sessions start to weigh upwards 3 gb and I don't use the package variant but rather the old way with folders. It's connected somehow. I also wish there was a way to delete all flex info from a file after the editing is done. 

[David Nahmani]

I've always experienced lagging with lots of edge its (several hundred audio regions). I remember having to bounce down some section before I move to the next to avoid that lag. I can't remember which Logic version it was, probably 6 or 7.