Currently I'm use FTGL library to render the text (texture font used) in my OpenGL application. I'm found a strange behaviour on different configurations with it. While the old system with GeForce FX5500 and Intel P4 have a very small CPU load (2-3%) my developer system take up to 70% (one core) AMD Phenom X2 550 load to render just several lines of the text!!!
OS not in the case - both Linux (Ubuntu 9.10) and Windows (tested Windows 7) are slowdown. Tested Catalysts versions 9.6-10.1 on AMD RadeonHD 3870. But users reports normal CPU load on oldest drivers and hardware (ATI Xpress 1200 + Catalyst 7.6).
I can't find the rootcause in my application (or FTGL library - code looks fine) - most CPU clocks are done in system OpenGL driver library (Catalyst). Tried to use AMD Codeanalyst.
My application - sView 2009 alpha (not the old sView 2008 version). Test case: launch an application from start menu (sView/sView - Image Viewer) -> open longest menu ("Anaglyph Red/Cyan" -> "Change Device" for example) and look for CPU load.