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WinRAR Version 5.00 Beta 2
Download WinRAR x86 (32 bit) 5.00 beta 2 or WinRAR x64 (64 bit) 5.00 beta 2
1. New RAR 5.0 archiving format.
You can use the "RAR 5.0" option in the archiving dialog or the command line switch -ma to create RAR 5.0 archives.
Older software including older WinRAR versions is not able to 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 the 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. The 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 a higher compression ratio and lower speed than RAR 4.x 4 MB. You can use the "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 no longer 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 the same extent as in the compression algorithm, this 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;
b) file names and archive comments use UTF-8 encoding.
4. RAR 5.0 recovery record improved
The recovery record is now based on Reed-Solomon error correction codes.
If the recovery record size is large enough (5 or more), the new error correction scheme provides much higher resistance to multiple damages compared to the RAR 4.x recovery record.With smaller record sizes, such as 2 or less, random damage would result in less difference between 4.x and 5.0. For single continuous damage 4.x and 5.0 efficiency is about the same.
In addition to usual data erasures, the new recovery record is able to detect deletions and insertions of much larger size than in previous RAR versions. Maximum insertion size is several megabytes. Maximum deletion size depends on the damage type and in some cases can be as large as the recovery record size.
Still, the best recovery performance and efficiency is achieved if no deletions and insertions are present, so that all data including damaged sectors have their original positions preserved. Thus, if you use some special software to copy an archive from damaged media, it is better to choose to fill damaged sectors with zeroes or any other data, instead of cutting the damaged parts out completely from that file.
RAR 5.0 recovery record is more resistant to damage of the recovery record itself and can utilize a partially corrupt recovery record data.
Note, the "Repair" command does not fix broken blocks in the recovery record. Only file data can be corrected. After successful archive repair, you may need to create a new recovery record for saved files.
Any new recovery record is not based on 512 byte sectors as previous as it incorporates more complicated data structures. So it is impossible to specify its size in sectors.
For RAR 5.0 archives the parameter of the -rr[N] switch and rr[N] command is always treated as a percentage of the archive size regardless of the presence of any characters.
Typically N recovery record can repair up to N of continuously damaged data and increases the archive size by only slightly more than N. The ability to fix multiple damage is proportional to N.
We used the "Screaming Fast Galois Field Arithmetic Using Intel SIMD Instructions" paper by James S. Plank, Kevin M. Greenan and Ethan L. Miller to improve Reed-Solomon coding performance.
Also we are grateful to Artem Drobanov and Bulat Ziganshin for samples and ideas that then allowed us to make Reed-Solomon coding more efficient.
5. "Test" command verifies the validity of the RAR 5.0 recovery record.
The recovery record is tested after processing all archived files.
If a corrupt archive contains the recovery record, it might be possible to repair it even if the recovery record validity test fails.
The "Repair" command attempts to utilize even a partially damaged recovery record. So treat the negative recovery record test result as a reason to re-create the archive if the original files are still available, not as a reason to avoid "Repair" command.
6. Changes in RAR 5.0 encryption algorithm:
a) encryption algorithm is changed from AES-128 to AES-256 in CBC mode.
Key derivation function is based on PBKDF2 using HMAC-SHA256;
b) the special password verification value will detect most wrong passwords without the need to unpack the entire file;
c) if archive headers are not encrypted ("Encrypt file names" option is off), file checksums for encrypted RAR 5.0 files are modified using a special password dependent algorithm, to make it impossible to guess file contents based on checksums.
Do not expect such encrypted file checksums to match the usual CRC32 and BLAKE2 values.
7. RAR 5.0 archives now allow the use of 256 bit length BLAKE2sp hash
Instead of using 32 bit CRC32 as a file checksum, RAR 5.0 now allows the use of 256 bit length BLAKE2sp hash (see https://blake2.net for details).
Enable the "Use BLAKE2 file checksum" option in the "Options" page of the archiving dialog or specify -htb command line switch to use BLAKE2 checksums.
While producing slightly larger archives, BLAKE2 can be used for file contents identification. If two files have the same BLAKE2 value, it practically guarantees that both file contents are the same. BLAKE2 error detection is also stronger than the much shorter CRC32.
8. Features removed:
a) authenticity verification feature does not provide the required level of reliability and was removed;
b) switch -en (do not add "end of archive" block) is not supported by RAR 5.0 archives, which always have the end of archive block.
This block helps WinRAR to safely skip external data like digital signatures appended to an archive;
c) old style extension based arcname.rNN volume names are not supported by RAR 5.0 archives, which use only arcname.partN.rar volume names;
d) file comments are not supported anymore both in RAR 4.x and RAR 5.0 archives. Console RAR 'cf' command is removed.
This does not affect the archive comment support, which is present in both versions of the archive format and is not planned for removal.
9. "Set password" command and "Dictionary size" option
These have been moved to the "General" page of the archiving dialog.
10. Save symbolic links as links
You can use the "Save symbolic links as links" option on the "Advanced" page of the archiving dialog to save and restore NTFS symbolic links and reparse points as links, so their contents are not archived.
Command line equivalent of this option is the -ol switch.
A similar option for NTFS hard links is "Save hard links as links".
Its command line equivalent is the -oh switch.
Both options are available only for the RAR 5.0 archive format.
11. Added extraction only support for the XZ archive format.
12. Changes in recovery volume processing in RAR 5.0 archive format:
a) maximum number of RAR+REV volumes in RAR 5.0 format is 65535 instead of 255;
b) recovery volume operations are faster than in RAR 4.x;
c) in addition to recovery data, RAR 5.0 REV files also store service information such as checksums of protected RAR files. So they are slightly larger than RAR volumes which they protect.
If you plan to copy individual RAR and REV files to some removable media, you need to take this increased size into account and specify the RAR volume size a few kilobytes smaller than the media size.
13. Maximum path length increased
The maximum path length for files in RAR and ZIP archives is increased up to 2048 characters.
14. Wrong password detection
Command line RAR returns the exit code 11 if it detects the user entered a wrong password. This code is returned only for RAR 5.0 archives.
It is impossible to distinguish between a wrong password and data damage for RAR 4.x archives.
15. Archived file names moved
'v' and 'l' commands display archived file names at the end of the line, not at the beginning as before. Also some fields previously available in 'l' and 'v' output are now shown only by 'lt' and 'vt'.
'vt' and 'lt' commands provide detailed multiline information for every archived file.
'vta' and 'lta' also include service headers in the list.
16. Default Charset now ANSI
Now the default charset for filelists in commands like 'rar a arcname @filelist' is ANSI for both WinRAR and console RAR.
In previous versions it was ANSI for WinRAR and OEM for console RAR.
You can use the -scl switch to override this default.
17. WinRAR viewer
The internal WinRAR viewer can detect and display files in UTF-8 and UTF-16 little endian encoding.
18. RAR and WinRAR log file rar.log
UTF-16 little endian encoding is used in the RAR and WinRAR log file rar.log, so that Unicode file names are stored in the log correctly.
WinRAR automatically truncates the old rar.log file in non-Unicode format to avoid mixing different encoding in the same log file.
For RAR you need to delete any old rar.log manually, otherwise RAR will append UTF-16 messages to it.
19. Command line 'r' (repair) command
WinRAR 5.0 can now include an optional destpath\ parameter defining the destination folder for repaired archive:
rar r archive.rar destpath\
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