What does the number after 7-zip's -m switch mean?
- by AndreKR
7-zip has a command line switch to set the compression method, -m followed by a number, e.g.
-m0=LZMA.
What does the number (0 in the example) mean? Different numbers produce slightly different compression results and performance:
time 7z -m0=LZMA -mx=9 -ms=on -mmt=off
real 0m2.292s
user 0m2.190s
sys 0m0.080s
time 7z -m1=LZMA -mx=9 -ms=on -mmt=off
real 0m2.405s
user 0m3.240s
sys 0m0.070s
time 7z -m0=LZMA -mx=9 -ms=on -mmt=on
real 0m1.038s
user 0m1.920s
sys 0m0.150s
time 7z -m1=LZMA -mx=9 -ms=on -mmt=on
real 0m1.187s
user 0m2.800s
sys 0m0.130s