How to compress PS2 ISO files?

I have been trying to compress some of my PS2 ISO's to save some space on my HDD, but I have been experiencing troubles with some of the ISO's. The smaller ones were compressed with no problems, but recently I tried several times to compress Devil May Cry III ISO (3.775.136 KB) and its respective .mds file (5 KB) using 7zip, but it just takes forever. For every second it spends in the process of compressing, the remaining time goes up 2 minutes. When I tried to leave it overnight, for about 8 or 9 hours, the process was stuck at about 30% and with 247 hours or so remaining. Similar issues occur with other ISO's.

Is there a specific setting that I need to adjust on 7zip, or maybe a different compressing tool that would work better?

Give these 7-Zip settings a go

My PC's barely what I need for emulation of PS2 anyway but compression is fine, I'll show my specs

Once I managed to compress GTA - SA within 10-15 mins on a high compression setting, I'll give it as an example

Attachment 36544

Ultra takes up too much RAM on LZMA2; my PC can do it but it drastically slows down my PC for ages since my RAM is only 4GB (required is about 2GB)

EDIT: Give WinRAR a go as well, sometimes 7-Zip goes weird so I use WinRAR instead and the .part1.rar and the .part2.rar is pretty good

Thank you for your help, ndsplayer, but I tried these settings and the same problem occured. But maybe that's because my PC sucks so bad. The only difference I got was that the maximum number of CPU threads I could set was 2 (after the dash on the right of this setting, where your image displays "/4", mine shows "/2").

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Originally Posted by Flávio Alves

Thank you for your help, ndsplayer, but I tried these settings and the same problem occured. But maybe that's because my PC sucks so bad. The only difference I got was that the maximum number of CPU threads I could set was 2 (after the dash on the right of this setting, where your image displays "/4", mine shows "/2").

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Thats my thread count; I have 2 cores, 4 threads

Can you give your PC specs anyways? Just to make sure and while you're there give a lower compression setting a go

Another problem it could be is to do with the algorithm of the 7z, in this case give LZMA a go

EDIT: I'm assuming you've given the algorithms a go already, try doing a zip file (or rar with WinRAR)

EDIT 2: Sorry for asking a lot, but could you give me the settings of the first time you compressed the ISO?