PA Comparison with WinZip is unfair

[deipotent]

On the main PA web page you claim

“Create unlimited sized ZIP files with fast and strong compression that outperforms WinZip.”

While this is probably true, and PA does create slightly smaller ZIP archives. WinZip has a crucial advantage over PA in that it automatically detects if the archive will be bigger than 4GB or contain over 65535 files. This is why the ZIP archives are slightly bigger.

PA has to have this option set by the user before the archive is created.

Don’t get me wrong, I prefer PA and it is my main archiver, but I think PA should also have this feature.

[klumy]

I support this wish

[spwolf]

Hi,

PowerArchiver has an option “Make large ZIP archive”, which will automatically detect if you need to use 4.5 spec format for large archives. If you check this option, and create smaller file than 4 GB- PowerArchiver will correctly detect that you do not need PkWare 4.5 format and will use 2.0 format instead.

That has nothing to do with compression size, they both store same header info, PowerArchiver just creates smaller archives…

thanks for the thought…

[deipotent]

Why bother having this option in the first place then ? There’s no point.

You might as well enable this option by default, and remove the option from the GUI. Insted you could replace it with an option “Notify if Zip64 archive created” which, if enabled, would display a message telling the user that “…a Zip64 archive was created. This will only be compatible with other applications that support the Zip64 standard.”

[awo]

@spwolf:

PowerArchiver has an option “Make large ZIP archive”, which will automatically detect if you need to use 4.5 spec format for large archives. If you check this option, and create smaller file than 4 GB- PowerArchiver will correctly detect that you do not need PkWare 4.5 format and will use 2.0 format instead.

But in this thread, you wrote: “Flag makes PA create archives in PkZip 4.5 format, and a lot of other archives can not read files create with 4.5 format…”. Isn’t that a contradiction?

[spwolf]

@deipotent:

Why bother having this option in the first place then ? There’s no point.

You might as well enable this option by default, and remove the option from the GUI. Insted you could replace it with an option “Notify if Zip64 archive created” which, if enabled, would display a message telling the user that “…a Zip64 archive was created. This will only be compatible with other applications that support the Zip64 standard.”

Option was originally made long time ago - when nobody but PA and PkWare had support for creating large archives, so most likely by creating this kind of archive you would not be able to share it with anyone.

We were already planning to remove it from PA 2005 since by now there are enough programs that support PkWare 4.5 to make it redundant.

thanks!

[deipotent]

I still don’t fully understand because in your original reply you said that PA would use 2.0 format when possible, only using the new 4.5 standard (ie. Zip64) when the resultant archive would be larger than 4GB or it contained more than 65535 files in it.

If this is the case, then there was never really a need for this option in the first place.

From a previous post by you a while back, you said that if this option was not enabled and you tried to create an archive greater than 4GB or with more than 65535 files, it would create a broken archive.

I’m confused……

Does PA automatically detect if 4.5 standard should be used, or not ?

[TBGBe]

With the flag NOT checked, PA uses 2.0 format and does not check if this results in an invalid archive.

With the flag checked, PA uses 2.0 format unless Archive would be greater than 4GB - in which case it uses 4.5 format. Checking the number of files 65535 is easy to understand.

Just wondering, without performing the compression first - how does PA “guess” the (not yet) generated Archive size ? Presumably this also depends on the actual compression options : maximum, normal, store etc.

[deipotent]

@TBGBe:

With the flag NOT checked, PA uses 2.0 format and does not check if this results in an invalid archive.

With the flag checked, PA uses 2.0 format unless Archive would be greater than 4GB - in which case it uses 4.5 format. Checking the number of files 65535 is easy to understand.

Just wondering, without performing the compression first - how does PA “guess” the (not yet) generated Archive size ? Presumably this also depends on the actual compression options : maximum, normal, store etc.

Now I get it. Has someone checked that PA automatically creates a 4.5 format archive with an archive that ends up larger than 4GB but has less than 65535 files ?

[spwolf]

I personally dont have technical knowledge of how does our zip component do that - originally we were not too trusty if it will actually correctly work (if it will be able to correctly guess which format to use) but after few years of using it - it works fine. Without looking at ZIP header/central directory info, I would guess it is done “on the fly” - since header information is different for each file.

So if you leave “Make large zip archive” checked, PowerArchiver will automatically detect if 4.5 format needs to be used or not. It might seem as if option is not needed anymore, but again - at the time we introduced it, it was needed or at least we thought it was so.

In any case, you are safe to leave it checked and it will work perfectly fine.

thanks,

[spwolf]

@deipotent:

Now I get it. Has someone checked that PA automatically creates a 4.5 format archive with an archive that ends up larger than 4GB but has less than 65535 files ?

Yep, it has been working fine for 2.5 years now. As mentioned above, I think it is done on the fly so once treshold is reached, 4.5 format is used.

thanks,