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Calculating file sizes

File size is limited by the restraints of the operating system and the available memory space on your hard drive or disk (depending to which you save the file). Software for Windows and MacOS may have different limitations due to system restrictions. Release HIstory details.

Windows OS

AcqKnowledge 64-bit and Biopac Student Lab 32-bit

There are multiple cases (configs) related to the issue of Memory/HardDrive/32bit-64bit limitations

AcqKnowledge  64-bit offers big improvements in terms of file size and memory limitation

File functions

Memory functions

BSL 4.1.2 or above

File and memory functions are unchanged at 2 GigaSamples of length and 4 GBytes of file size. BSL 4.1.2 or above can allocate max 2 GBytes of RAM for transformations.

MacOS


Use the following equation to calculate the memory required for your acquisition:

 Memory required (bytes) = [(8C + 2A) x S x T] + 1 MB*

C = Number of calculation channels
A = Number of analog channels
S = Sample rate (samples/second)
T = Recording time (acquisition length; when sample rate is samples per second, T is in SECONDS)
* 1 MB = MINIMUM memory overhead required to store file information
  • Journals, events, and other information are variable and will also require more disk space.
  • Once analog channels are filtered or otherwise transformed, the required amount of storage will increase to 8 bytes per sample, identical to calculation channels.
  • It is not possible to perform any transformations for acquisitions where converting analog channels to floating point will exceed 2 GB.
  • Memory overhead requirement may increase significantly with
    • many events with long labels
    • long and rich-formatted journal
    • opened DataViews
    • MetaChannels – overhead includes Hardware Settings and MetaChannels support (max 16 metachannels per each of 16 calc channels –> 256 “calc” channels)
    • Smart Amplifier information as part of Hardware Settings section of graphfile take storage

Note that all 16 digital channels allocate 2 bytes (16 bit – 1 bit per digital channel). So, having at least 1 digital channel ON will cause allocation of 2 bytes  per sample.

Refer to the software guide available under the program Help menu for setup and analysis guidelines when working with large files.

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