There are many programs providing a similar feature-set, as hashing data is not exactly a new invention. This comparison will therefore focus on the tool that inspired the creation of godi in the first place, mhl.

As the latter doesn't provide the ability to copy data while it hashes it, a program called DoubleData or ShotPutPro could be used for comparison in that regard. However, as there is no free version of these available, there is no comparison just yet.

Comparison to MHL

MHL, media-hash-list, is a command-line utility to seal and verify data. It's somewhat specialized to data produced in the media industry.

Benefits over MHL

• Performance
  • godi is up to 6x faster in tests on a quad-core laptop CPU, but will scale with more cores and higher available device bandwidth to reach even higher speeds.
    • Those inclined may maximize bandwidth by tuning parallelism
  • Will read in parallel from multiple devices, leveraging all device's maximum bandwidth.
  • Can write to multiple devices at once, creating multiple duplicates of your data as fast as your slowest writer. If one device fails, all other devices will still receive their duplicates, whereas the failed device will not have an intermediate result.
• Usability
  • godi just works. mhl will fail (for some reason) if it finds files it doesn't want to handle, and it ignores symbolic links. godi has no implicit ignore lists, and may be fully customized to suit your needs. By default, it will just ignore volatile files, like .DS_Store.
  • mhl has a gather stage to investigate all files before it does anything. Even though this information is used to show how much more data it has to process, it will take a lot of time on big datasets. godi will start in the moment you hit enter, and inform you about any progress regularly.
    • For some reason, mhl presents the total amount of bytes to process according to the amount of bytes it has to hash. This can be confusing.
  • godi comes with a state of the art commandline interface, allowing to learn the command by using it. No manual required. mhl has it as well, but it's inconsistent, the front page (mhl [help]) doesn't inform about all available sub-commands and help topics. You will find the missing ones referenced in help-texts of the available topics.
  • mhl seals are not protected against being altered. File corruption or intentional changes can't be detected, and will lead to invalid verification results.
  • mhl doesn't escape characters interpreted by XML, producing invalid MHL files in case a & character is in a file path, without telling you. This can be a real issue, have a look at this demonstration to see it for yourself
    • I would have left a note, but the discussion forum doesn't exist anymore.
  • During verify, mhl will just check one of the sha1 or md5 hashes, in that order, which leaves room as tiny as a billionth atom to accidentally verify a file. godi will verify against all hashes it has taken.
  • godi is available for more platforms and architectures, mhl is 'only' available for windows, linux and osx (all 64bit).
• Features
  • Copy or archive on the fly
    • While hashing, you can also transfer the data, reading it only once in the process. With mhl, you need to copy first, and hash afterwards, which reads the data twice. godis operation assumes the storage works correctly, however, there is a safe mode which verifies the copy nonetheless.
    • It will never overwrite existing files.
  • Atomic Operation
    • It will not produce intermediate results, and either finish successfully, or leave no intermediate files at all
    • Particularly useful when copying or archiving, as it will not leave any written file(s), allowing to safely abort and retry at will. The latter is good during performance tuning.
• Open-Source and active Development
  • Everyone is free to look at and modify godis source code. mhl is closed source, downloads are behind a form to retrieve your e-mail address, and the last life-sign was posted July 18th 2013

Benefits of MHL over godi

• Executable Size and Memory Consumption
  • The mhl executable is only 131kB (OSX) to 1.5MB in size, whereas godi clocks in at 3.5mB. This is due to differences in how the program is compiled.
  • mhl just uses about 712kB of memory when processing small amounts of files, whereas godi needs about 4mB for the same dataset.
• Automatic Handling of Meta-Data
  • mhl will include more information, including a full operation log, in the generated mhl file, whereas godi leaves gathering this information to the user.
• Special Handling for Image Sequences
  • As mhl comes from the media industry, it may read and check frame sequences specifically.
• Advanced Seal File Handling
  • mhl is able to produce hashes individually and create mhl files from the output of various commands. For example mhl hash -c /path/to/folder/*.mov | mhl file -s -v -o /path/to/folder and openssl dgst -md5 /path/to/files/ -name "*.mov" | mhl file -s -v -o /path/to/folder are possible applications.