Depending on the OS and further application restrictions, the
SWI-Prolog RDF stores scales to about 15 million triples on 32-bit
hardware. On 64-bit hardware, the scalability is limited by the amount
of physical memory, allowing for approximately 4 million triples
per gigabyte. The other limiting factor for practical use is the time
required to load data and/or restore the database from the persistent
file backup. Performance depends highly on hardware, concurrent
performance and whether or not the data is spread over multiple (named)
graphs that can be loaded in parallel. Restoring over 20 million
triples per minute is feasible on medium hardware (Intel i7/2600 running
Ubuntu 12.10).
