ORIGINAL: SteveFoobar
Has anyone figured out what the new Record Pre-allocate File (seconds) is really for and when and how to best use it? I've searched the entire thread archive and haven't found anyone mention it's function. It's under the Options, Audio, Advanced, Playback and Recording area.
There seems to be no mention of it in the online help or the PDF that I can find.
Pre-allocation just means reserving (allocating) a specified amount of space on the hard drive prior to recording (as opposed to "on-the-fly" which is what happens normally). Reasons for pre-allocating may include:
1. More efficient writing with less interruption. The disk is freed from finding the next unallocated space, de-allocating it, and setting up the file links from the previous allocation to this new allocation (disk management tasks). Instead, the hard drive can just read the file links and tell the application where to write the next group of data.
2. More contiguous file allocation on the disk. If more than 1 file is being allocated on-the-fly then it's possible that each file is becoming fragmented and interleaved with each other as they each continually ask for more space on the disk. With pre-allocation, file A asks for all its space, then file B asks for all its space, etc which can lead to more contiguous allocation depending on the fragmentation of the free space on the disk.
There are some questions though:
1. When the pre-allocated space becomes fully used, does the system revert back to on-the-fly allocation or does it perform another pre-allocation of equal size? (see below)
2. If you pre-allocate for 60 seconds and only record for 30 seconds at the end of recording does it go back and truncate the file to 30 seconds or leave it as 60 seconds with 30 seconds of silence? Does using pre-allocation ending using a lot of hard drive to store a bunch of zeros? I suppose some experimentation could figure this out (set pre-allocation for like 5 minutes, record for 10 seconds, and see how big the file in the audio directory is afterwards).
I could see pre-allocation being useful for very long recordings. If a live show will take about an hour, then pre-allocate for say 70 minutes. Then the files would already be created ahead of time and just need to be filled in with the sample data. However, if you run over the pre-allocation time and it attempts to pre-allocate another 70 minutes for each recording track you'd almost definitely get a dropout. If it reverts back to on-the-fly, then things would probably be ok.
I suppose they added this advanced feature to help hard drives that have a difficult time switching between reading/writing and file/disk management functions since allocation procedures can be consolidated somewhat.
But without any documentation all of this is just guessing on my part...
