Reports priview for rendering PDF output is taking time in 12c(12.2.1.3) reports than 11g (11.1.2.2)

Hi,

We have performance issue for reports 12c(12.2.1.3), preview for rendering the PDF output is taking more time than the reports 11g(11.1.2.2), which are connected to the same database. We have same OS level patch, same code and the 11g rdf's, forms and pll's are compiled in 12c but the database is same. All are same except the forms & reports version difference. We are calling the reports from forms and then previewing the reports with PDF output. We are having two nodes each with 32G of total memory out of which swap is 16gb and 4 virtual CPU's. Here our