Apart from all that @richgalloway already mentioned, this document shows results of testing on some particular reference hardware. It's by no means a guarantee that an input will work with this performance. Also remember that windows eventlog inputs get the logs by calling the system using winapi whereas file input just reads the file straight from the disk (most probably using memory-mapped files since it's most effective method). And last but definitely not least - as I already pointed out - UF typically doesn't break data into events! ... View more