Using OpenGL with MythTV
While fine-tuning our MythTV system, I noticed that the default menu-renderer is QT. There's nothing wrong with QT, except that it doesn't offer hardware acceleration that OpenGL does. So, using QT creates a higher system load on the MythTV frontend. This takes away CPU cycles that could be better spent, and provides a UI that is less smooth.
So, I enabled OpenGL menu-rendering for MythTV (0.21) only to find the menu transition taking a horrendous amount of time. There was an OpenGL fade that occurred on each screen transition that would take about 5 second to complete. This is when I realized that I should have installed the vendor's X Windows driver.
My MythTV machine has an NVidia GeForce FX 5200 graphics card installed. It's a few years old, but works perfectly for this purpose: fanless, hardware OpenGL rendering & MPEG-2 decoding, and DVI output. I went to the NVidia support site and downloaded the display driver. I then installed it and marveled at how much it improved everything. The system load was greatly reduced because the OpenGL rendering occurred in hardware, menu navigation was very quick, and a lovely fade effect occurs upon each screen transition.
So, the lesson learned was to install the NVidia display drivers when choosing OpenGL menu rendering with MythTV. OpenGL is a great improvement over QT, and having display drivers that can take advantage of hardware acceleration is a must.