Alesis iO14 Reference Manual page 50

Getting In Deeper: Recording
8
Geek talk: Why do we multiply by 3?
We have to multiply our disk usage by 3 because we assume you'll be recording at 24 bit. One
"byte" of disk space contains 8 "bits" of information. Thus, if you are recording at 24-bit
resolution, you'll need 3 bytes to contain all of that sample data (since 3 x 8 = 24). This is why
your disk usage must be multiplied by 3.
If you were recording at 16 bit (which we do not recommend due to the reduction in sound
quality) you would only multiply your total by 2 since a 16 bit sample only needs 2 bytes to
describe the sample (2 x 8 = 16).
If all of this sounds like Martian to you—don't worry. You don't really need to know this stuff and
there's no quiz at the end of the manual!
2. Processor Usage – A second drawback of recording in high
definition is that you'll use substantially higher amounts of
CPU resources. This is because your computer processor has
to deal with twice as many samples operating at 88.2k than it
does when processing at 44.1k and four times as many
samples when recording at 176.4k. The following
hypothetical scenario should clarify:
Sample Rate
44.1/48k
88.2/96k
176.4/192k
If you generally don't use many audio tracks and plugins, this
won't affect you very much. If you use tons of audio tracks
and plugins, this may tilt you in favor of recording at a lower
sampling rate (or get a faster computer if you insist in
recording in HD).
3. Fewer ADAT optical inputs – If you're using an external
analog-to-digital converter to add more inputs to your
IO14/26, you can add 8 (IO|14) or 16 (IO|26) channels at
44.1 or 48k, but you can only add 4 channels of 88.2k or
96k audio.
48
Maximum Plugins you can
run on your computer
40
20
10
The ADAT2 port on the
IO|26 is only operational at
44.1k and 48k sample rates.