DOS ain't dead

2008-05-05

- Some speed optimizations.
- 7-Zip now can unpack .lzma archives.
- Unicode (UTF-8) support for filenames in .ZIP archives. Now there are 3 modes:
1) Default mode: 7-Zip uses UTF-8, if the local code page doesn't contain required symbols.
2) -mcu switch: 7-Zip uses UTF-8, if there are non-ASCII symbols.
3) -mcl switch: 7-Zip uses local code page.
- Now it's possible to store file creation time in 7z and ZIP archives (-mtc switch).
- 7-Zip now can unpack multivolume RAR archives created with "old style volume names" scheme and names *.001, *.002, ...
- Now it's possible to use -mSW- and -mSW+ switches instead of -mSW=off and -mSW=on
- Some bugs were fixed.
- New localizations: Punjabi (Indian), Pashto.

Home page:
http://www.7-zip.org/

Downloads:
http://www.7-zip.org/download.html
or
http://sourceforge.net/project/showfiles.php?group_id=14481

> 2008-05-05
>
> - Some speed optimizations.

It's a lot faster (esp. decompression) than 4.57 in my tests. Definitely worth the upgrade.

[ WinXP ] Wed 05/07/2008>7za457 b

7-Zip (A) 4.57  Copyright (c) 1999-2007 Igor Pavlov  2007-12-06

RAM size:     511 MB,  # CPU hardware threads:   1
RAM usage:    419 MB,  # Benchmark threads:      1

Dict        Compressing          |        Decompressing
      Speed Usage    R/U Rating  |    Speed Usage    R/U Rating
       KB/s     %   MIPS   MIPS  |     KB/s     %   MIPS   MIPS

22:    1048   100   1019   1019  |     9903   100   1020   1020
23:    1012   100   1031   1031  |     9784   100   1021   1021
24:     975   100   1051   1048  |     9622   100   1017   1017
25:     743    81   1045    849  |     7246    77   1012    776
----------------------------------------------------------------
Avr:           95   1037    987                94   1018    958
Tot:           95   1027    973

[ WinXP ] Wed 05/07/2008>scrndump a.txt

=======================================================================

[ WinXP ] Wed 05/07/2008>7za b

7-Zip (A)  4.58 beta  Copyright (c) 1999-2008 Igor Pavlov  2008-05-05

RAM size:     511 MB,  # CPU hardware threads:   1
RAM usage:    419 MB,  # Benchmark threads:      1

Dict        Compressing          |        Decompressing
      Speed Usage    R/U Rating  |    Speed Usage    R/U Rating
       KB/s     %   MIPS   MIPS  |     KB/s     %   MIPS   MIPS

22:    1133   100   1102   1102  |    12712   100   1147   1147
23:    1110   100   1135   1131  |    12547   100   1148   1148
24:    1073   100   1153   1153  |    12383   100   1151   1149
25:    1014   100   1158   1157  |    12170   100   1144   1144
----------------------------------------------------------------
Avr:          100   1137   1136               100   1148   1147
Tot:          100   1142   1141

[ WinXP ] Wed 05/07/2008>scrndump b.txt

> > 2008-05-05
> >
> > - Some speed optimizations.
>
> It's a lot faster (esp. decompression) than 4.57 in my tests. Definitely
> worth the upgrade.

I've noticed - didn't test as systematicaly as you did, but was able to notice reduced time in large jobs.

One issue: Larger archives than with 4.57. Tested by now in large and small jobs, on mixed file types. Very small percentage difference, possibly a trade-off for better speed.

> New localizations: Punjabi (Indian), Pashto.

On DOS ? Screenshot please

FYI, I did bother to test:

- Still works with HX
- Faster: 1.09x compression, 1.2x decompression
- Better compression (15 ppm ... yeah)

Compared against 4.42.

---
This is a LOGITECH mouse driver, but some software expect here
the following string:*** This is Copyright 1983 Microsoft ***

> > New localizations: Punjabi (Indian), Pashto.
>
> On DOS ? Screenshot please

The localizations work in the Win GUI. How to see: Run under Windows. Do you read both Punjabi and Pashto?

> FYI, I did bother to test:
>
> - Still works with HX
> - Faster: 1.09x compression, 1.2x decompression
> - Better compression (15 ppm ... yeah)
>
> Compared against 4.42.

4.42? Who cares?

> localizations work in the Win GUI. How to see: Run under Windows.

Useless.

> you read both Punjabi and Pashto?

YES. Not necessarily full understand, though.

> 4.42? Who cares?

Me.

---
This is a LOGITECH mouse driver, but some software expect here
the following string:*** This is Copyright 1983 Microsoft ***

> - 7-Zip now can unpack .lzma archives.

This may be because some GNU projects are using it (e.g. GNUzilla) in distribution archives instead of Bzip2 (see here for example).

> > 4.42? Who cares?
>
> Me.

During testing of the 4.58 alphas, it was mainly compared against the more recent / "stable" 4.57, and it still wins. However, this is probably due more to using a more recent MSVC compiler on select modules during compilation (although I'm sure Igor manually tweaked the src a bit himself).

> One issue: Larger archives than with 4.57. Tested by now in large and
> small jobs, on mixed file types. Very small percentage difference,
> possibly a trade-off for better speed.

Some are bigger, and some are smaller. It seems to vary widely. The only quick example I could find of bigger (vs. 4.57) was trying to compress 3 .PDF files (and the difference was only 10 bytes, so no big loss).

> > One issue: Larger archives than with 4.57. Tested by now in large and
> > small jobs, on mixed file types. Very small percentage difference,
> > possibly a trade-off for better speed.
>
> Some are bigger, and some are smaller. It seems to vary widely. The only
> quick example I could find of bigger (vs. 4.57) was trying to compress 3
> .PDF files (and the difference was only 10 bytes, so no big loss).

My tests on EXEs, text and ZIPs all produced larger 7z files. But I'll stay with 4.58 anyway - speed and bug fixes are worth a few bytes.

> My tests on EXEs, text and ZIPs all produced larger 7z files. But I'll
> stay with 4.58 anyway - speed and bug fixes are worth a few bytes.

I think he's storing file creation timestamps now, so that probably bloats up the header a tiny tiny bit. Anyways, it's less than 1% difference, so it's no biggie. You can also use "-m0=ppmd" instead of default LZMA, but that uses lots more memory.