#1239 decompression is much slower then if you would 7zip (same content)

[Johan Compagner]

can we improve the descompression somehow?

If i have an installer, a zip file or a 7zip file of exact the same content then the difference between using the installer or 7zip to uncompress the zip or 7zip file is huge:

33s 7zip (as 7zip)
35s 7zip (as zip)
1m42s installer

i really wonder why that is 3 times as slow...

[Anders]

I can think of at least 3 reasons

• NSIS just uses a single extraction thread.
• Probably slower handling each file so if you have many files, that will add up.
• Probably uses smaller buffers so there are more calls to WriteFile which ends up as more kernel transitions.

How large is this archive? What does it contain?