PSP Technique - Convert ISO to CSO

After you understand how to copy UMD disc into ISO game file. It ready to play. Then why people want to compress it into .CSO file (compressed ISO file)? The reason is they want to reduce the size of ISO by ripping out unwanted parts inside it so they can put more game on the small MMS. The software popular to do this task called UMDGen4.
You can download it here -- > http://pspslimhacks.com/downloads/util/UMDGen4.rar

How u will do:

For this example I’m going to use Metal of Honor Heroes 2 which I just converted to an ISO from my UMD disk. Open UMDGen, then click OPEN and browse to your ISO file. Select that, UMDGen will load the UMD up. See below, I have Metal of Honor Heroes 2 loaded. Note the file size is 1169.94Mb in total. Lets see if we can slim that down a few megabytes….

Above is a general view of UMDGen ver. 4.0

Step 1: Ripping out unwanted parts ( or optimize the ISO file)

Now in UMDGen lets click the Properties tab. You’ll see various UMD info. Ignore all that what we want to do is click Optimize image (look for it at bottom left corner) this will remove the update folder and any padding on the image. (padding out the data helps UMD’s load faster). In my case here we saved 4.05% on the disk size. Not much I know but with some games this can be over 15%.

See the result on the bottom left as shown above

Step 2: Reduce size by compressing it to CSO file

Now its time to compress this ISO into a CSO, now click the SAVE button on the TOP and select .cso and name your file and select the save location.

I’m going to go with a compression level of 9 here. If it lags, reduce this value.

After the task finished, copy it to MMS and try. If it lag or so slow or not run smoothly, try to reduce compression level to 7 or 8. Try more times then u will get experience to do it more better

My Medal of Honor.cso file is now just 357mb! thats a huge saving in size from 1169.94Mb. Now I can place more games on my memory stick than if they were iso files.