Originally posted by pschlute The computer has a 240gb ssd; a 4 gb video card memory; 16 gb RAM; and 2 TB hard disc
The basic specification seems fine for PS and LR although the SSD may be a little small if you have a lot of applications. If this is the case then consider loading some applications on your 2TB spinner (be aware that some applications will still take some SSD space) to leave room for the heavier duty applications.
Ideally keep at least 25% free space on SSD - they too will/can experience slow down when near full.
As stated earlier PS will use as much RAM as you have, or rather allow it to make use of. Make changes in Preferences depending on your system. 16GB should be plenty for most users even running concurrent applications (video editing excluded!). Set up your scratch disk in this case to use your SSD as this is the fastest at data transfer if needed and also a secondary target of your HDD.
Key to PS running and memory requirements, keep an eye on the Efficiency indicator. PS slowdowns will occur if the system running out of RAM as the program will need to read from the scratch disk. If you find that it is constantly dropping and staying below 90% (and you get a noticeable slow down) then the indications are that the system would benefit from either allocating more memory or increasing the physical RAM. Note PS will write to scratch disk regardless of RAM amount, this will not slow performance, but having to read data back from scratch is the slow down culprit.