One File Per Track Option; Reducing Unnecessary Disk Access; Track And Mixer Muting - Merging Pyramix User Manual

The first issue is the size limitation of the WAV and BWF formats. These are LIMITED TO 2 GB in size by design (they
use 32 bit signed, which gives a total of 2 to the power of 31 Bytes addressable = 2'147'483'648 Bytes precisely).
2GB may sound a lot but a little elementary arithmetic will show it is easy to exceed this limit when using higher
sample rates and bit depths for multi-track recordings of real-world durations.
AIFF is slightly better in the sense that it is "only" LIMITED TO 4 GB (it uses 32 bit unsigned, which gives a total of 2
to the power of 32 Bytes addressable = 4'294'967'296 Bytes precisely.
PMF uses 64 bit addressing which would probably allow 128 tracks to be recorded for about 10,000 years (If you
can afford the disks!), which should be more than enough for any practical applications.
The second advantage of the Pyramix File Format for large multitrack projects is that it is not "sample-interleaved"
but "block-interleaved". Which means that instead of (as with WAV, BWF and AIFF) recording on disk one sample of
channel 1, then 1 sample of channel 2, and so on to 1 sample of channel n, .pmf was designed from day one to
optimize disk access by recording a quite large block of samples for each channel in a sequence. Typically 64 kB of
channel 1, then 64 kB of channel 2, etc, finally 64 kB of channel n.
This setting (default 64 kB) can be changed by the user to one of four alternative values in the Record Block Size
section of the Playback/Record page of All Settings > Settings > Application . However, the alternatives are
really only applicable to certain RAID and Network-Attached-Storage set-ups and, unless you have considerable
knowledge and experience, the default setting should be used.
Note: PMF is optimized for interleaved multi-channel as opposed to single.

One File Per Track option

For non PMF formats
Found in the All Settings > Settings > Project > Record page, The One file per track option should always be
chosen (checked) whenever more than 2 tracks of recording are contemplated as there is a rather high potential
performance penalty that can occur with all the (non PMF) sample-interleaved file formats (E.g.WAV and AIFF) on
playback, when not all tracks of a multi-channel recording are used or played in their original sync relationship on
the Timeline. This is because with other, interleaved, formats the hard disk head will still have to go through all the
bits of all the channels, even if only 1 or 2 tracks of that file are used at a given point in time.
For maximum performance with One File Per Track choose BWF in preference to PMF .

Reducing Unnecessary Disk Access

Track and Mixer Muting

There is a subtle difference between muting a Track Output (with the
the same signal in it's associated mixer input strip. Muting a Track stops disk access for the Track (There is a delay
before the sound stops while the replay buffer is emptied). Muting a mixer strip doesn't affect disk access but sim-
ply mutes the strip (Therefore muting is immediate). Muting Track outputs enables multi-track recordings with
many Tracks (E.g. 48 Track music recordings) to be edited on hardware which cannot support this number of
Tracks. (E.g. a laptop) Providing the Clips are grouped across all Tracks, then any editing changes made on the
Tracks used for the editing guide will also be reflected in the muted Tracks. Track Grouping can be used to make
operation simpler and more convenient.
Productivity : Optimizing Pyramix
button in the Track Header) and muting
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