WinRAR - What's new in the latest version
1. New RAR 5.0 archiving format. You can use "RAR 5.0" option
in archiving dialog or -ma command line switch to create
RAR 5.0 archives.
decompress RAR 5.0 archives, so if you plan to send an archive
to other people, it is necessary to take the compatibility issue
into consideration. You can select "RAR" instead of "RAR5" option
in archiving dialog to create RAR 4.x archives compatible with
previous WinRAR versions.
2. Changes in RAR 5.0 compression algorithm:
a) maximum compression dictionary size is increased up to 1 GB
in 64 bit WinRAR. 32 bit WinRAR version can use up to 256 MB
dictionary when creating an archive. Both 32 bit and 64 bit
versions can unpack archives with any dictionary size,
including 1 GB;
b) default dictionary size for RAR 5.0 is 32 MB, typically resulting
in higher compression ratio and lower speed than RAR 4.x 4 MB.
You can use "Dictionary size" archiving dialog option or -md
switch to change this value;
c) -md switch syntax is modified to support larger dictionary
sizes. Append 'k', 'm' and 'g' modifiers to specify the size
in kilo-, mega- and gigabytes, like -md64m for 64 MB dictionary.
If modifiers are not present, megabytes are assumed,
so -md64m is equal to -md64;
d) RAR 5.0 format includes Intel IA-32 executable and delta
compression algorithms, but RAR 4.x text, audio, true color
and Itanium algorithms are not supported. These excluded algorithms
are not efficient for modern data types and hardware configurations;
e) RAR 5.0 decompression can utilize several CPU cores.
Though not to same extent as in compression algorithm,
it improves the decompression speed on large files
with poorly compressible data or when using BLAKE2 checksums.
3. Changes in RAR 5.0 archive format:
a) file times are stored as Coordinated Universal Time (UTC)
instead of former local time, making file exchange among
several time zones more straightforward;