Complex sentence: Optical disc recorders detect the available speed options based on the data which is available on the disc itself; however, some low quality discs make a high speed option available to the software, while the burning process can never reach that speed in practice.
Split into simpler sentences: Optical disc recorders detect the available speed options based on the data which is available on the disc itself. However, some low quality discs make a high speed option available to the software, while the burning process can never reach that speed in practice.