#2504 Performance problem vs 2022-01

[FCS]

Hello,

On version 2201-x64 the compression of database dump file of 105GB takes 22 min
On current version 2408-x64 the compression of this file takes 32 min.
It's about 50% longer.
Why? What happened since the 2201 version ?

I use this command:

"C:\Program Files\7-zip\7z.exe" a -tzip -mx=3 f:\arch\xxx_%date% f:\arch\xxx.dmp

Regards
ML

[Igor Pavlov]

check it again and add -bt switch that shows compression time:

7z a -tzip -mx3 -bt a.zip file 

[FCS]

Hello,

I know the compression time because the command is a part of batch file.

echo Kompresja: %Date% %Time% >> C:!Bat\dump.log
"C:\Program Files\7-zip\7z.exe" a -tzip -mx=3 f:\arch\xxx%date% f:\arch\xxx.dmp
echo Kopiowanie : %Date% %Time% >> C:!_Bat\dump.log

after C: is '\' (not visible here)

so I exactly know how many time it takes

on version 2201
Kompresja: 2024-08-22 23:19:11,85
Kopiowanie: 2024-08-22 23:41:51,83

on version 2408
Kompresja: 2024-08-27 23:16:40,07
Kopiowanie : 2024-08-27 23:48:08,92

I updated last weekend from 2201 into 2408.

Regards
ML

[Igor Pavlov]

-bt switch also shows cpu usage load.
for example, if you have only one core on VM and some another process uses that single core, then 7-zip has low cpu resources.

What is your CPU?
Also check that new version is 64-bit (x64), and is not 32-bit.
Maybe data is different and larger?
Did you compare compressed and uncompressed size?

Also maybe antivirus software can check created zip file and consume cpu resources at some stage?

[FCS]

Hello,

It is new server 16C/32T.
7zip works on hardware server not in VM.
The longer time is after installation of the new version.
The source database dump binary file of course changes in time, but it is still about 105 GB.

I go back to 2201 version to see again how long time it takes.
As you see the process starts at night, so will send tomorrow results of last iteration.

The time may depend of the structure of compressed file.
I tested locally on different computer the compression of 1.7GB MP4 file, and new version was 1s faster then the old ( 64s vs 65s but it is in the same range )

Regards
ML

[Igor Pavlov]

mp4 file is compressed already.
Look compressed and uncompressed size for your database file.
If you want fast compression, use xz format instead of zip:

7z a -mx1 mx1.xz file
7z a -mx3 mx3.xz file
7z a -mx5 mx5.xz file

7-Zip will use all 32 threads of cpu for xz format.

[FCS]

Hello,

On the version 2201 the time of compression during the last iteration is the same as on 2408

Kompresja: 2024-08-28 23:20:03,05
Kopiowanie: 2024-08-28 23:52:16,10

and takes 32 min.

I will observe the next iterations, because at this moment I have no idea why the time grows from 22 into 32 min. Probably any external cpu usage may occur or the content of database binary file changed even if the size of this file not grows a lot.

2024-08-28
dump: 105 729 490 944 b
zip: 41 839 881 944 b

2024-08-27
dump: 105 665 097 728 b
zip: 41 826 197 485 b

Regards
ML