With Lightroom, I have the application on my internal SSD, the database on the internal SSD and the Cache on the internal SSD. The photographs I am currently working on the internal SSD whilst completed images are on external hard drives.
Now that I am looking a getting a new computer, one of the options is to use my old laptop for occasional light use, my wife’s laptop for heavy use when I need power and portability; and the new computer for maximum power and colour critical work together with the Adobe RGB monitor.
This will entail moving between Lightroom databases, possibly having a master Lightroom database on the main computer and a working database that gets moved between the other machines.
While Lightroom works well with importing and exporting databases into other databases, one of the options I have been testing recently is putting the working database and photographs onto an external drive, possibly an external SSD.
It seems that the key to getting performance out of Lightroom is raw processor power. As long as the application is on the internal SSD, and the Lightroom Cache is on the internal SSD then the database and photographs work quite happily on a external drive, either FireWire 800, ThunderBolt or USB3 (USB2 not quite so well).
The camera RAW cache settings depending on Lightroom version is between 1 and 5 GB. This is far to small. For a laptop 20 GB was recommended, and 100 GB for a desktop, since Lightroom V4 Adobe have changed the cache format so 20 GB may be enough for both laptop and desktop use, unless your catalogue is particularly large. If you use DNG or convert to DNG, then its also important you have fast load ticked.
For now, I am going to create a new Lightroom database on a LaCie external drive that is both FireWire 800 and USB3 and keep switching between my laptop and my wife’s laptop and see how I get on. If its works well I may invest in a G Tech ev drive and dock. The dock can be left connected to the desktop I buy.