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?