#PSP Win 10 USB ISO Loader install#
#PSP Win 10 USB ISO Loader drivers#
#PSP Win 10 USB ISO Loader iso#

Back then the compression algorithms they used were heavy on CPU and RAM, so they would often use weaker algorithms with weaker compression, or even no compression at all, so that FMVs would go smooth. To finish it off: I highly recommend compressing media files as that actually helps reduce stutter and even aliminates it on many games via USB.

#PSP Win 10 USB ISO Loader iso#

The results was that all compressed formats, including CSO, were now performing very well, very close (if not equal) to ISO speeds.įor PS2 of course I implemented an optimized reader algorithm like Inferno has, and the ZSO format uses the extremely fast LZ4 decompression algorithm that doesn't require any extra RAM and works just fine on the PS1 CPU dressed as a co-processor that Sony calls IOP.

#PSP Win 10 USB ISO Loader drivers#

Most recent readers like the latest Inferno Drivers found in PRO, ARK and Adrenaline solve this issue by introducing caches that minimize IO and an algorithm that tries to read all compressed data at once rather than block by block to also reduce IO. This is because reading a file from an ISO (let's say a 520KB file) requires only 1 constant IO call no matter the size or where in the file it is, but the same read on a compressed format (whichever it is) results in a linearly growing amount of calls since you have to read arbitrary offsets withing the file and read block by block. The results were clear: barely any changes. It was thought that the issue was the decompression speed, which is why JSO and (later) ZSO were created: with the idea in mind that a faster decompression would result in no stutter or high loading times. It is actually a bad idea to NOT compress audio and video data as opposed to what people used to believe.īack in the early days of PSP CSO format the FMVs would stutter like crazy for two big reasons: slow memory sticks and absolutely no optimizations on the reader algorithms that would yeild EXTREMELY high IO operations.

#PSP Win 10 USB ISO Loader install#

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).