Moving catalog to external SSD?

[rexxiong]

Hi, I have LR classic on 2019 iMac with 512G internal SSD.

Right now:

1. I put the catalog and previews in the internal SSD (speed should be 2G/s from reviews)

2. Use an external Samsung T5 SSD (speed should be 500M/s from reviews) to store the fresh photos I took (A7R4 RAW, about 120MB per photo)

3. After reviewing and editing fresh photos, I move them to NAS (1Gbps) 

The issue I met is as my catalog grows (130K photos), catalog and preview files are too huge to fit in internal SSD.

Several questions need help here:

1. As I read some posts here, storing raw images files in SSD or HDD doesn't make much difference, so step 2 above is not necessary? I can put files in NAS directly?

2. If I want to move catalog and preview to external SSD, is my current Samsung T5 good enough (500M/s)? Or I should look for something like Samsung T7 (1G/s)? or even Thunderbolt SSD?

3. Is my single catalog too big? (130K photos), shall I split?

Thanks

[Ian Lyons]

Based on the 2TB Samsung T5 SSDs I have here, you should expect a realworld Write speed of approximately 420MB/s whilst the Read speed will be approximately 380MB/s. My 2TB T7 SSDs have a realworld Write speed of approximately 780MB/s and Read speed of approximately 710MB/s. Both are connected to the front Thunderbolt ports on my Mac Studio Ultra using the Samsung supplied USB-C to USB-C cable, although connecting to USB-C ports should present no performance issues. Liikewise, you should experience no peformance issues using either of these SSD drives for your catalogs, although I suggest you aim for the 1TB or 2TB versions rather than 512MB. This will give your catalog and previews plenty of growth space.

My master catalog contains 140k of images, and there are others who visit the forum with catalogs containing in excess of 1 million files. Splitting you catalog is unlikey to bring any realword performance benfits when using SSD drives to store your catalog and previews.

l

[richardplondon]

On the current step 2, I only see that as helpful if you are sometimes importing new photos on the move, when the NAS is not (readily) accessible. If so, clearly a temporary folder filing structure within that portable drive should match the one within the NAS, to ease that later move of the files. Or this initial location could be onboard (just for fresh photos taken on the move) and that's a more slimmed-down travel setup. But if your Catalog is going to be within that external drive then you couldn't do without that.

Otherwise so far as a main setup, it's my firm opinion that image files should be handled only once (at time of their import). That way they appear in your backup regime - already at their longterm location - as early as possible, and then be left fully alone. Moving files around for workflow reasons is both more inflexible and less efficient IMO, compared with the fluid virtual management that the Catalog offers.

As an example: say after processing a photo, you later make a new virtual copy for some different purpose. The Catalog can manage and characterise these two image versions 100% independently of each other, and unrestricted by their (incidental) shared reliance on the same source file.

[rexxiong]

Thanks for reply, if I'm at home with NAS available, the only benefit seems to be faster import time (300M/s to ssd limited by sd card read speed vs 100M/s to NAS limited by 1Gbps network). But if I import to ssd first, it will require another move to NAS, so the total workflow time still longer

[dj_paige]

Most of the import time is consumed by the CPU generating previews. So, different disk speeds for previews will have only a trivial impact on import time.