WinRAR v4.20 FINAL Español Oficial + Portable, Potente Compresor en Ficheros RAR, ZIP

a) RAR general compression algorithm is optimized for better
utilization of several processor cores. While some speed gain
is possible even in single processor mode, best results
are achieved in multi-core environment.

Speed gain depends on data type and average file size.
Several cores are utilized more efficiently when compressing
large files.

b) we had to increase memory requirements to achieve higher
compression speed. General RAR compression algorithm allocates
about 120 MB comparing to 40 MB in WinRAR 4.11;

c) RAR text compression algorithm cannot utilize several CPU cores
efficiently, so its performance in multiprocessor environment
is much lower than for general algorithm. Also its decompression
speed is much lower than in general algorithm regardless of
CPU number. So we decided to disable the text algorithm by default.

If you need maximum possible compression ratio for plain text data
regardless of speed, you can enable the text compression
in “Advanced compression parameter” dialog. Press “Compression…”
button on “Advanced” page of archiving dialog to access it.
You can also change this option permanently in default compression
profile;

In the command line mode the text compression can be enabled
with -mct switch;

d) “Fastest” (-m1) compression mode also supports several processor
cores now. In 4.11 it could use only a single processor core.