To install ZSO files to internal HDD, use the version of hdl-dump attached in the release page.Ĭlick to expand.The CSO/ZSO format specification already has a mechanism to skip compressing blocks if it detects that the resulting compression doesn't have much of a gain. Other devices such as HDD and SMB are also known to work well, with HDD having no lag at all on any game.Īlways Download the latest OPL builds from the Official OPL Github Release Page. I've tested the following games on a Fat PS2 with USB:Ĭomparison of ISO and ZSO performance in the same USB device (an external SSD):

I've been working on this feature for about a week now and the results are incredible: many games now fit and run 100% perfect with zero lag on USB devices (great examples being MGS3, Shadow of the Colossus, GTA 3 and Vice City, Resident Evil 4 and more). Those of you from the PSP scene might remember this format, it's the good old CSO but using LZ4 instead of DEFLATE (much faster and lighter). One of the upcoming features for OPL 1.2.0 will be support for ZSO format (compressed ISO images).