I am using the latest version of BC4 in OSX, High Sierra.
Recently, I am suffering from a speed issue about BC4.
I do not know that the problem occurs from the latest version of BC4 or High Sierra.
Please check this problem.

I use...
OSX High Sierra 10.13.1
BC4 Version 4.2.3 (build 22587)
Mac Pro (Late 2013)
3.7 GHz Quad-Core Intel Xeon E5
64 GB 1866 MHz DDR3