Performance tuning

Almost all time is spent in the checksum algorithm. To improve performance, you can use MD5 instead of TIGER, which will give some 20 per cent improvement (on Linux/i686). To switch to MD5, use the DigestAlgo option in the configuration file:
  [Misc]  
  # use MD5 
  DigestAlgo=MD5 
  

Other things you can do are:

On the other side, if you want to reduce the load caused by file checking, you can change the scheduling priority (see man nice), and/or limit the I/O:
  [Misc]
  # low priority (positive argument means lower priority)
  SetNiceLevel=19 
  # kilobytes per second
  SetIOLimit=1000
  

Similarly, for the SUID check, you can limit the files per seconds:
  [SuidCheck]  
  # limit on files per seconds
  SuidCheckFps=250