run a Windows machine, not Mac. But in my experience the only way to get really fast is to have both the catalogue and photos on the internal HD. At a minimum the catalog needs to be on the internal drive. Not realistic with a large catalog for image files to be on the internal drive
This is a "My PC can only have one internal drive" centric viewpoint.
A PC can have multiple internal drives (including laptops), and they're usually better performers than USB external drives.
BOOT: SSD NVMe, as usual, don't put anything here but OS/Apps
INTERNAL NVMe: my desktop photo editing machine has 2 (besides the boot). My road trip laptop as one extra.
- One holds the LR catalog and previews
- The other is scratch and ACR cache, plus I edit projects that require the extra performance (over HHD / External USB / NAS)
Upsides: this is the very fastest, best performing option, even more so than the external SSDs.
Downside: They're relatively smaller sized (1-4TB) and more expensive than HHD
Laptops: You can get laptops that take 1-2 NVMe drives (besides the boot drive).
INTERNAL HHD: these are still a thing you know
- Right on the SATA bus
- Not taking up space externally
- No wires
- Very LARGE sizes (up to 20TB)
- Affordable (very much more so than SSD)
Laptop: many laptops offer an internal 2.5" HHD in addition to the boot NVMe drive. Those can be pretty large (2-4TB), though they seldom come that large from the factory (you have to upgrade it yourself or pay someone else after market). You might be able to order them special with the larger internal HHD.
EXTERNAL HHD
- This probably applies more to the OP and anyone doing remote work with a laptop
- This is a popular option for Mac users that don't want to fuss with the whole expandable/extensible PC thing (be able to add and upgrade internal drives as the needs arrive)
Downside: typically the slowest option, takes space.
EXTERNAL SSDs
- Plug-in SSD drives, very popular with a lot of you traveling with laptops on road trips. Steve has videos on this. Very robust, cost effective, you can keep multiple copies, etc.
- You can get external enclosures for NVMe drives. Not as robust for travel as the plug-in SSD drives, also more expensive, but very performant. This is probably the least likely choice for most of us.
On Topic Recap: my travel laptop has a boot NVMe SSD, an internal 2.5" 2TB HHD, and a extra non-boot NVMe SSDs. It might not be common, but it's doable.
Chris