I would never expect a photo editing app to be what you’d call lightweight, but there have been several times this app alone has caused my otherwise snappy M1 MacBook Pro to feel laggy.
When I’d open Resource Monitor it’d show that Lightroom was using between 5-8GB RAM on its own. I don’t recall that being an issue, at least not to this degree, when I first got Lightroom.
By today’s standards admittedly 16GB RAM isn’t high end, especially for photo and video editing. But damn if literally every other aspect of using this computer feel fine, even editing 4K video runs smooth.
I looked into it on various forums and evidently this is normal for Lightroom, sadly.
Others say that the app routinely eats more than half their system memory — even those with 32GB RAM. Most of those people recommend shutting down most of your other apps in the background, and in some cases closing and reopening Lightroom to get it to let go of RAM.
The reason being that Lightroom apparently doesn’t free up RAM well between each photo you’re editing, so if you’re working on quite a sequence of photos the whole collection you’ve touched, complete with all the edits, are stuck in RAM and don’t release until the app is closed.
That means that if you’re editing a sequence of images, it’s not use RAM and then release between photos, but rather keep eating RAM with every batch of edits until the RAM is gone.
I find this seems to happen less noticeably on my iPad Pro than my MacBook — maybe because iPadOS is more locked down.
However, I still notice the normally buttery smooth performance of the M1 iPad Pro becomes a little jittery after a few photos sometimes. Especially if I’d used several masks.
It reads like this isn’t a bug or an oversight, that Adobe does this intentionally to maximize performance for those jumping back and forth between a bunch of images. I get that, but I wish there were an option in the app settings to limit how many edits are saved in previous images.
Personally, I’m only concerned about the image I’m currently working on. If I need to return to a previous one I’m ok with a momentary load. That’s less of a burden than a system starved for RAM because one app is going crazy and everything else suffers for it.
Just my two cents.