This is just a quick review of how fPDF stands up against tcPDF in the area of performance at each libraries most basic functions.
17.0366 seconds to process 2000 PDF files using fPDF || 79.5982 seconds to process 2000 PDF files using tcPDF
788 fPDF || 1,860 tcPDF
The code used was as identical as possible and renders just a clean PDF file with no text. This is also using the latest version of each library as of June 22, 2011.