A really impressive white paper/book with insights about Tabular performance and inner-workings. Kudos to the authors for producing this colossal resource.
“Tabular models hosted in SQL Server 2012 Analysis Service provide a comparatively lightweight, easy to build and deploy solution for business intelligence. However, as you increase the data load, add more users, or run complex queries, you need to have a strategy for maintaining and tuning performance. This paper describes strategies and specific techniques for getting the best performance from your tabular models, including processing and partitioning strategies, DAX query tuning, and server tuning for specific workloads.”