Screen savers, alarms or reminders, and incoming faxes will kill disc writing. You should also turn off network sharing so that no one tries to access the files you're trying to write - this would also fatally interrupt writing. The Hard Disk Speed To write a virtual image on the fly to compact disc, the hard disk from which you are writing MUST have a transfer rate fast enough to keep the memory buffer full in the CD recorder. This usually means an average hard disk access time of 19 milliseconds or better. Thermal Calibration Most hard disks automatically periodically perform a thermal calibration to ensure proper functioning.
Calibration interrupts hard disk operations for as much as one and a half seconds.
Some hard disks force a calibration at fixed intervals, even if the disk is in use, causing interruptions fatal to real-time operations such as CD writing. This problem arises particularly when the amount of data to be written is large. Some hard disks calibrate intelligently, postponing it when the disk is being used. Fujitsu and many Micropolis hard disks work this way. Data is transferred from the computer's hard disk to the buffer memory of the CD recorder, and thence to the recording laser, which inscribes pits into the surface of the CD at a steady speed which cannot be altered or interrupted.