Limit of total number of columns for dataset table returned from procedure.

In my report, I have 7 tables and these table are huge. Each table query are similar to one another which uses same 6 tables but uses different columns. Instead of executing query 7 diferent time, I combined together and runs much faster but since then there has been more changes. New columns added and some calculated column in the stored procedure. Now I return 131 columns. Still performance is not been issue and so far still One is better than seven . Now I have to add 10 more, AGAIN. If I am reaching the limit of totoal number of columns then I want to break to two or three.

My question is how much is the limit for total number of columns. any good suggestion on what should I do

Thanks in advance