Apple MacOS continues to change. When I last stopped diglloydTools IntegrityChecker java ("icj"), some parameters gave the fastest performance. These parameters from 10.13.6 and 10.14 now result in a significant drop in value .
The native version of IntegityChecker JDK for use with diglloydTools IntegrityChecker is Java 11 or OpenJDK 11.0.2.
The download page has not yet been updated, but it is easy to make the result change,
1. Open / Programmer / diglloydTools / icj in any plain text editor (eg TextEdit).
2. Look for the line with PERF_PARAMS. It will look something like this; change IO_BUFFERS_PER_THREAD to 2 and change IO_BUFFER_SIZE to 1
export PERF_PARAMS = "- DNUM_THREADS = 0 -DIO_BUFFERS_PER_THREAD = 0 -DIO_BUFFERS_PER_THREAD = 0 -DIO_BUFFERS_PER_THREAD = 0 -DIO_BUFFERS_PER_THREAD = 0 2 -DIO_BUFFER_SIZE = 1024 -DSMALL_FILE_SIZE_CUTOFF = 1 $ ENCODING_TEST $ ENCODING "
These parameters can be experimented with, but from February 2019, they give the best performance to both single hard drives and fast SSDs.