What does underflow on I/O channel mean?


Thread Starter


Hello forum participants,
I know what underflow means in computations but what does it mean in connection with I/O channels ?

Yours sincerely
Ariel Burbaickij


I think this term makes sense for analog I/O only, where it would means that the measured value goes below the lower limit of the conversion range. This, IMHO, could also or even more precise be called "negative overflow".

John G. Boland

Hi Ariel,

Is your reference to "I/O channels" part of a more detailed error message?

Failure to transfer data rapidly enough across an I/O channel, for example, to the write buffer when writing a fast CD-R, causes what is known as a "Buffer Underrun" error.

"Underflow" could be the same as "underrun", that is, for one reason or another, when data is not received over the I/0 channel at an adequate
rate and the receiving end runs dry.


John G. Boland, president
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Diana C Bouchard

The term "underflow" or "underrun" is often used with regard to burning CDs. The condition occurs when the flow of data from the computer fails to
keep up with the write speed of the CD burner, and the data buffer empties out.

Diana Bouchard
Pulp & Paper Research Institute of Canada (Paprican)
Pointe Claire, Quebec, Canada
[email protected]