And so are recording speeds. However, many buffer underruns are not buffer underruns at all, but some other phenomenon that causes the recording software to return that error. This can be the result of recorder command set errors poorly interpreted by software, or a faulty recorder. We all know that buffer underruns occur when the computer is unable to transfer data to the recorder fast enough to keep the recorder's buffer full. Because recording is a real-time process, the data must flow in a steady uninterrupted stream to make recording successful.
Many factors can affect the data stream, and slow it down or interrupt it completely.
Some are true enemies of successful recording, and others are not. Hardware, software, and source media can all affect the recording process. On the hardware side, the culprit is usually the source you are recording from, whether that is the hard drive holding the files to be recorded, or a CD-ROM drive, ZIP, JAZ, or other removable media. It is unlikely in the modern desktop computing environment that either of these will be the case. Modern hard drives are plenty fast, and most manufacturers have remedied the thermal recalibration problem.