Creating of ZIP files very slow

Help & Support
1

Hi!

Just wondering whether it's normal and i have to live with the fact that the creation of zip files in DOpus is about 3 to 5 times slower than with 7-zip.

  • creation in DOPUS with "Copy ZIP HERE"
  • creation with 7-zip via right click and "add to folder_name.zip"

Some examples:

  1. Folder with 126 files and 7 folders, 67 MB: most of them pdf, jpeg, zip
  • DOPUS: 6 seconds
  • 7-ZIP: 1 second!
  1. Folder with 237 files and 30 folders, 35 MB: some pdf, png, zip, many tex files
  • DOPUS: 3 seconds
  • 7-ZIP: <1 second

The resulting file sizes are more or less the same. But 7-ZIP files are slightly smaller. Both compression rates are "normal"

DOPUS 10.0.2.0 64 bit (fresh install) on Win7 here.
7-ZIP is also 64 bit, version: 4.65

2

Maybe I've got an idea: 7-zip probably uses 4 threads, which could make the difference on a quadcore cpu.
Does DOPUS use only one parallel thread?

3

That's an easy theory to test: Set 7-Zip to use one CPU.

4

FWIW, if you enable ZipX in Opus and then compress to that, you'll be using the same 7z.dll code as 7-Zip itself.

("ZipX" in Opus really means "use the 7z.dll Zip code." Aside from the file extension, I think it will produce a standard Zip file, not using any of the extra ZipX compression modes, unless I've forgotten how it works. It's called ZipX since enabling it allows some ZipX files to be extracted and since Opus has its own Zip code there isn't usually any other reason to enable it. It's not enabled by default because the underlying 7z.dll code doesn't support all of the extra ZipX compression modes and will throw errors when extracting some ZipX archives.)

5

It may also come down to the types of files being compressed. Maybe Opus is trying to compress PNG and other files which are not worth compressing while 7-Zip has heuristics that say "just store a file, uncompressed, if it has a .PNG extension."

6

Thanks, Leo, for your answers!

Indeed, that seem to slow down 7-zip (as expected).

So, how would I create ZIP files with 7z.dll?

  • enable ZipX plugin
  • run which custom command?
  • maybe rename the file? it should really be a normal zip-file than.

Alternatively, it would be OK to run a command which create a zip file with the 7-zip executable.