CSU’s only use Math and Critical reading in calculating your Eligibility Index (EI). They use the EI to rank applicants for each major and then accept applicants from the highest EI down until all the spots are filled.
EI= (CSU GPA x800) + (SAT Math + CR)
If you take the ACT, the CSU’s use the ACT composite in the EI calculation.
(CSU GPA x200) + (ACT Composite x10).
I would try the ACT so see if you can score better. Both my son’s did much better on the ACT vs SAT. Colleges accept either one.
SJSU is the only CSU that publishes their EI threshold each year for each major. It will give you a ball park on what you need to aim for in your testing.
http://info.sjsu.edu/web-dbgen/narr/admission/rec-10079.12651.html