What is the maximum RAM Lightroom can use?

[MarcySB]

I am using Windows 10 on an HP desktop computer with 16 Meg of RAM and the newest version of Lightroom. I am wondering – is Lightroom able to use all of the RAM available?

Thanks, Marcy

[dj_paige · Accepted solution]

YES

[99jon]

Hi Marcy

I’m guessing you mean 16GB? You can find out what is being used when undertaking Lightroom tasks by going to Task Manager (Windows) or Activity Monitor (Mac) but I would expect LR to leave a percentage of available RAM for other open applications or multi-tasking.

[Conrad C]

Lightroom can use 16GB of RAM or more, but most of the time, it won't need all of it. From watching my system's memory manager, Lightroom uses the most RAM when it's merging multiple large raw images into a panoramic or HDR image. When you develop a single image, Lightroom can probably leave much of the 16GB RAM for other applications to use.

[rodlaird]

"...most of the time it won't need all of it"...

My experience is that when working with large numbers of images (e.g. ingesting and processing shoots / trips that may have hundreds / thousands of images), LR room will indeed use massive amounts of memory. I have on occasion see it use up to 72GB of an available 128GB. It may hold previews in memory I suspect - and with 60 to multi-hundred Mpx images, the little dribs and drabs add up...

If you aim to use LR intensively I would alway invest first in all the memory your system can handle - it is the cheapest performance debottlenecker. THen of course NVME SSD's for image caching. (Though I use the no longer available Intel Optane as a primary cache and dial RAID 1 NVME SSD's as second level cache). And finally a fast HDD subsystem helps if you can afford one - by which I mean a hardward RAID5+ or RAID10 system with lots of fast SAS HDDs. Lots of fast CPU cores also helps - along with a heavy duty GPU.

Adobe have actually done a pretty remarkable job of making LR usable evon on limited resource systems. But unlocking its full potential takes quite a lot of work (and, unfortunately money). The leverage of multi-core systems is increasingly effective, which is terrific. The base code of LR is however not terribly efficient as and of itself - so one can look for more significant performance improvements in the future as the code base is modernised...

Good luck  - enjoy the journey - and get more RAM!

[Conrad C]

I’ve changed my thinking since I posted that reply five years ago. Up until recently Lightroom Classic didn’t need much memory when editing a single image, and only seemed to need more than 20GB when merging multiple images, for example into a panorama.

But in more recent versions, especially since version 12, I am seeing Lightroom Classic use up to 30GB more often on my Mac with 32GB memory. (That doesn’t cause a performance problem because the amount can include data that is compressed in RAM or cached, so all open applications, and there can be many of them, continue to run smoothly.)

I wonder if the increased memory use is related to things like the recently expanded masking, use of GPU acceleration, and use of AI. That increased memory usage doesn’t bother me, if it means it’s making the most use of the computer’s resources to let me do things both faster and at better quality.

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@rodlaird wrote:

If you aim to use LR intensively I would alway invest first in all the memory your system can handle - it is the cheapest performance debottlenecker.

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Maxing out any spec is not necessarily cost effective. A MacBook Pro laptop can now be specced with 96GB of memory, at a price premium of $800 over the base model; the Mac Studio compact desktop can take 128GB. For many Lightroom Classic users, 32–64GB is the sweet spot and the value of going above that is questionable, and the amount that could have been spent to get it to 96GB or 128GB will usually be better spent on other components.