Yes. Tally.Server 9 is multi-threaded.
The Tally.Server 9 technology is built with multi-session capabilities, such that requests from every user get equal priority and get solved in parallel with others, rather than sequentially. There is no queuing of accessing the requests and every user will feel as if he is working with his own local copy or snapshot of data. Tally.Server 9 will ensure that the data access by a user is isolated to his/her own snapshot, thus allowing other users to operate smoothly. Tally.Server 9 will give you a Concurrent Read + Read and Concurrent Read + Write as well.