Lightroom and SSD

I have been dealing with 120 different catalogs that total 1.5 TB. My 2019  MacBook Pro has 8 TB ssd. I have had my catalogs on the mbp and my photos on a 36 TB G-Raid Thunderbot 3 drive. 

for some reason, over the years I have noticed that the LR catalogs will hang on the ssd drive. When doing faces and similar intense operation. Especially if my catalogs are big. Over 50,000 images. 

In my experiments over time, I have noticed that my catalogs would slam through the processes when they reside on the raided hhd drives. They are somewhat slower, but it seems that the spinning disk will get the job done and not "hang". It is a bit slower, but more reliable in my opinion. 

So over the years I have kept my catalogs on my laptop ssd and my photos on hhd's. 

just last night, I finally decided that ssd is not the best for Lightroom.  There is something wrong with the way LR works with ssd's. Yes, most things work and they work fast on an ssd, but then when you do big operations... you get the hang. This has happened to me from 2015 up and to now. Anyway, I am reorganizing my catalogs to sit with the photos and it feels good. Everything in one place and I know that even the the hhd is slower, it's much more reliable. 

There can be waiting on the hhd... but it's not hanging. 

has anyone else experienced similar experiences?

RichardFlack  wrote Im getting new computer that will have SSD, and trying to decide what size of SSD. 1) Am I correct that its good to have the LR catalog on SSD? 2)  What about the Library images themselves?   (I import with 'copy to DNG' from an "original' folder what is basically my archive), is there any performance gain in having that on SSD?

1) YES Catalog on SSD

2) First a question.

Do you currently use LR on your older computer?

If you do there is NO reason to Import anything into LR on you new computer. You COPY over the catalog you are using on your older computer and open it on the new computer. Along with that you COPY over, in the same folder structure, all you images to the new computer. "IF" you currently have all your images on an External drive and that external is the WORKING location for your images on your old computer and you have to do is connect the external drive to the new computer and make sure it gets and retains the same drive letter it had on the old computer.

No reason to put images on the SSD.

To be on the safe side you should have at least a 500GB SSD. If you can afford it get a 1TB SSD. Or get the smallest and cheapest SSD option from the computer maker and then buy a 1TB SSD from someplace like NewEgg and replace it yourself. If you are building the system yourself then use a 1TB SSD to start with.

I'm going with the 512 GB SSD on the "more is more" principle (probably tripling the available space for things like LR catalog, I think about 100 GB goes to "system").

I do notice on my current computer (no SSD, 8 GB RAM) that LR does bog down from time to time, even switching between images.

The comment about putting catalog etc on there but not the images makes sense.   Image library is probably too big anyway (at 285 GB; catalog is about 35 GB w previews, if Im looking in the right place).

I'm thinking about performance while editing etc, not the initial transfer.

As dj alludes there is not much gain from having your images on the SSD. Biggest gain comes from camera raw cache, catalog, and previews on the SSD. However, with SSDs bigger is better and there are varying kinds. Some can do terabytes/second nowadays. So go as big and as fast as you can afford.

Photo files should go on regular spinning hard disks and not on SSD.

Catalog should go on SSD.

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