# Add to Archive Dialog Box

Allows you to specify options for creating or updating an archive.

#### How to call this dialog box

1. In Windows Explorer or in 7-Zip, right-click the file(s) or folder(s) you want to compress.
2. Point to 7-Zip, and then click the Add to archive... command item.

#### Parameters

Archive
  Provides a space for you to specify a destination archive name. You can click "..." button to display "Open" dialog box that you can use to locate archive.
Archive format
  Specifies a format of created archive. Some formats (gzip and bzip2) do not support compressing more the one file per archive.
Compression level

  Specifies compression level. There are 6 levels of compression:

  Value | Meaning
  --- | ---
  Store | Files will be copied to archive without compression.
  Fastest | Fastest compression.
  Fast | Fast compression.
  Normal | Compression with balanced settings.
  Maximum | Can give a higher compression ratio than Normal level. But it can be slower, and it can require more memory.
  Ultra | Can give a higher compression ratio than Maximum level. But it can be slower, and it can require more memory.

Compression method

  Specifies compression method. Each archive format can have its own compression methods:

  Method | Description
  --- | ---
  LZMA | Default compression method of 7z format. It provides high compression ratio and very fast decompression.
  LZMA2 | LZMA-based compression method. It provides better multithreading support than LZMA. But compression ratio can be worse in some cases. For best compression ratio with LZMA2 use 1 or 2 CPU threads. If you use LZMA2 with more than 2 threads, 7-zip splits data to chunks and compresses these chunks independently (2 threads per each chunk).
  PPMd | Dmitry Shkarin's PPMdH algorithm with small changes. Usually it provides high compression ratio and high speed for text files.
  BZip2 | Standard compression method based on BWT algorithm. Usually it provides high speed and pretty good compression ratio for text files.
  Deflate | Standard compression method of ZIP and GZip formats. Compression ratio is not too high. But it provides pretty fast compressing and decompressing. Deflate method supports only 32 KB dictionary.
  Deflate64 | Modified version of Deflate algorithm with bigger dictionary (64KB).

  Estimated 7-Zip performance and memory requirements for AMD Athlon 64 X2 3800+:

  Method | Level | Dictionary Size | Compressing Speed | Decompressing Speed | Memory for Compressing | Memory for Decompressing
  --- | --- | --- | --- | --- | --- | ---
  LZMA | fastest | 64 KB | 4.5 MB/s | 15 MB/s | 3 MB | 3 MB
  fast | 1 MB | 3 MB/s | 10 MB | 3 MB
  normal | 16 MB | 2 MB/s | 186 MB | 18 MB
  maximum | 32 MB | 1.8 MB/s | 376 MB | 34 MB
  ultra | 64 MB | 1.6 MB/s | 709 MB | 66 MB
  PPMD | fast | 4 MB | 1.4 MB/s | 6 MB
  normal | 24MB | 1.2 MB/s | 26 MB
  maximum | 64 MB | 1.0 MB/s | 66 MB
  ultra | 192 MB | 0.9 MB/s | 194 MB
  Deflate | fast | 32 KB | 15 MB/s | 40 MB/s | 3 MB | 2 MB
  normal | 3.5 MB/s
  maximum | 1.5 MB/s | 4MB
  ultra | 0.4 MB/s
  BZip2 | normal | 900 KB | 3 MB/s | 16 MB/s | 20 MB | 7 MB
  maximum | 1.2 MB/s
  ultra | 0.4 MB/s

Dictionary size

  Specifies Dictionary size for compression method.

  Usually, a higher Dictionary size gives a higher compression ratio. But compressing can be slower and it can require more memory.

  Memory (RAM) usage for LZMA compressing is about 11 times more than dictionary size. Memory usage for LZMA decompressing is close to value of dictionary size. Memory usage for PPMd compressing and decompressing is almost equal to dictionary size.

Word size

  Specifies the length of words, which will be used to find identical sequences of bytes for compression.

  Usually for LZMA and Deflate, big Word size gives a little bit better compression ratio and slower compression process. A big Word size parameter can significantly increase compression ratio for files which contain long identical sequences of bytes. For PPMd, the Word size strongly affects both compression ratio and compression/decompression speed.

Solid Block size

  Specifies the size of a solid block. You can also disable solid mode. In solid mode all files will be compressed as continuous data blocks. Usually compressing to a solid archive improves the compression ratio. You can use this option only for 7z archives. The updating of solid .7z archives can be slow, since it can require some recompression.

  .
Number of CPU threads

  Specifies the number of threads for compressing. A big number of threads can speed up compression speed on Multi-Processor systems. Sometimes it can increase speed even on single-core CPU.

Split to volumes

          {Size}[b | k | m | g]

  Specifies volume sizes in Bytes, Kilobytes (1 Kilobyte = 1024 bytes), Megabytes (1 Megabyte = 1024 Kilobytes) or Gigabytes (1 Gigabyte = 1024 Megabytes). If you specify only {Size}, 7-zip will treat it as bytes. It's possible to specify several values. Example:

          10k 15k 2m

  The first volume will be 10 KB, the second will be 15 KB, and all others will be 2 MB.

Parameters

  Allows you to specify parameters for compression. See the -m (Method) switch description for more details. Omit the -m prefix (as in -m switch) when using this dialog box.

  Examples

            0=PPMd

  uses PPMd method for compressing files.

            0=bcj2 1=lzma:d23 2=lzma 3=lzma b0:1 b0s1:2 b0s2:3

  uses BCJ2 filter (for x86 executables) and LZMA.

Update mode

  Specifies update mode:

  Value | Meaning
  --- | ---
  Add and replace files | Add all specified files to the archive.
  Update and add files | Update older files in the archive and add files that are new to the archive.
  Freshen existing files | Update specified files in the archive that are older than the selected disk files.
  Synchronize files | Replace specified files only if added files are newer. Always add those files, which are not present in the archive. Delete from archive those files, which are not present on the disk.

Options

  Specifies compression options:

  Option | Meaning
  --- | ---
  Create SFX archive | Create self-extracting archive. You can use this option only for 7z archives. Look to -sfx (Create SFX archive) switch description for more details about SFX modules.
  Compress shared files | Compress files open for writing by another applications.

Encryption

  Specifies password and encryption options.

  Enter password
    Specify password here
  Reenter password
    Reenter password here for verification
  Show Password
    Shows Password
  Encryption method
    Specifies the encryption method. For 7z format, it can be only AES-256. For ZIP format you can select ZipCrypto or AES-256. Use ZipCrypto, if you want to get archive compatible with most of the ZIP archivers. AES-256 provides stronger encryption, but now AES-256 is supported only by 7-Zip, WinZip and some other ZIP archivers.
  Encrypt file names
    Enables or disables archive header encryption, including file name encryption.