text: Title: speed up checksum checks for large files
  Body: Hey DVC devs!
  
  First off, a huge thank you for creating this brilliant project. It has been a game-changer for our data science projects.
  
  In our work with lot of large input files (2 - 50+ GB), we've noticed that the checksum checks for these files are incredibly slow. Is there any plan or interest in speeding up the checksum checks? Are there any options to utilize integrated file system checksums or faster implementations of checksum calculations?
  
  Thanks a ton!
  
  Tom