Students can read the detailed revised pattern of SAT, released by College Board Publically

The details of revised SAT pattern which is to be introduced from Spring of 2016 is released by the college board on 16 April, The detailed information of the new SAT pattern also include sample questions as well as explanations of the research, goals and specifications behind them. 
CyndieSchmeiser the College Board's chief of assessment, during the conference on this matter said that 211-page test specifications and supporting materials are to be shared publicly with focus laid on students, she stressed that studentsmust be aware of the new pattern completely and must not walk into that test to be surprised. 
The major changes are described in brief as follows:

One of the biggest changes is made in the vocabulary questions. In the revised SAT, the question paper will not include obscure words, rather the words thatCollege Board refers to as "high utility" words and the ones that appear in various contexts and in many disciplines will be put in the paper. Those words often will have shifting meanings — and they will betested in context.

The new SAT pattern makes the test to last for 3 hours duration along with 50 minutes extra being given to write an optional essay. In the essay part the examinees will be asked to analyze a text and would ask questions surrounding how the author builds an argument. The scores of essays will be recorded and reported separately from the other sections of the SAT.
The new SAT will introduce a 65-minute critical reading section in which 52 questions may be asked. Likewise, a 35-minute written language test will also held that may contain 44 questions. Furthermore, math section will be for 80-minutes and will throw 57 questions.

The language and math sections will each be scored from 200 to 800, and the top composite score will be 1,600.

The revised SAT will prohibit students from using Calculator in some sections while at present the test permits the use of calculator.

Instead of five multiple-choice answers given at present, the new test will offer only four options to choose the correct answer from. 
The revised SAT will include questions related to Interpreting the graphs and this will not be limited to just mathematics but will be a vital question area for analyzing science and social science texts as well.