To zip or not to zip (or 7zip)

[cowgod]

I have read so many posts and watched so many videos over the last two weeks that my mind has gone to mush.  Some people say using zip files for your roms is a bad idea because of save state compatability with RetroArch or other emulators.  Others say it's fine as long as you add zip/7z to the file extension list in HyperSpin.  There are also performance considerations to keep in mind with unzipping a game every time you want to play.  How do you all store your roms on Android, and why?  And what about on PC?

[Suhrvivor]

I'm on PC and 7zip everything smaller than a DVD, for PS2 ISOs I use gzip since the emulator can decompress them on the fly, same thing with GameCube and Wii with the Dolphin compression.

I'm not a fan of save states so I don't have come across issues for using compressed files. I guess that If you use the same file and set states' folders to be in the emulator directory It won't be a problem, at least on PC.

[Sncboom2k]

I currently use 7z as well (enabled in HyperSpin) and it works great. I do not use save states at this time so I have no info to share on that issue.  I am however now very interested in the following from Suhrvivor:

" PS2 ISOs I use gzip since the emulator can decompress them on the fly,"

How do you set that up? I would love to reduce the amount of time before being able to play a game etc.  Thank you!

[Suhrvivor]

If I'm no mistaken and since I don't tend to use save states much (seems like cheating to me), they are a problem because some times they're saved in the same directory where the rom or iso are decompressed and when you close the emulator, Rocketlauncher deletes the decompressed iso and the save state file so next time you launch that game you won't have the save state. You need to make sure that the emulator doesn't put the save states in the same directory of the rom or iso. 

 

To use gzip just grab any iso of a ps2 you have and compress them to gzip format (using 7zip). PCSX2 supports them for a while now.

Some considerations:

- If you use Rocketlauncher, make sure the new file extension is present for PCSX2, otherwise you'll get an error when you try to launch a game.

- The first time you load a gzip, PCSX2 will read the whole gzip file and make a cache of its structure, so don't be scared if you see nothing happening in the emulator window for a while (if you have the console enabled you'll see stuff happening there). Next time you load that gzip PCSX2 it will load it as fast as if it wasn't compressed! 

- The cache file will be created by default in the same directory as the gzip, so make sure you have permissions to create files there (you can change the directory by editing some ini files).

[BATTLEDONKEY]

For PS2 isos I compressed them all to .cso with maxcso.  Pcsx2 supports it natively, so the games boot up instantly and that way I don't have to deal with extra cache files and that initial load time for each game

[Sncboom2k]

Great! Thanks guys - I'll give those a try and use the one I like the best! Appreciate the info (and the ability to save some time.)

[nikkisixx]

I don't like using compressed files. The load times, the problem with the save/load states. I use save/load states because i have little time to play and perhaps i must stop a game in any moment and saving is very usefull to me.

The only bad thing is that they need more hard disk space... buy with another hard disk the problem is solved!

What i said is everything for PC. I don't use Android.

[Suhrvivor]

What's the problem with save states and compressed files?

[lohobernard]

Generally speaking most modern compression algorithms give roughly the same compression, and with regard to the number of cores that you can use at once, it is up to you to decide how many you want to use. However, 7-zip is free and open source. The 7z format supports encryption with the AES algorithm with a 256-bit key. The key is generated from a user-supplied passphrase using an algorithm based on the SHA-256 hash function. The SHA-256 is executed 218 (262144) times,[4] which causes a significant delay on slow PCs before compression or extraction starts. This technique is called key stretching and is used to make a brute-force search for the passphrase more difficult. Current GPU-based, and custom hardware attacks limit the effectiveness of this particular method of key stretching,[5] so it is still important to choose a strong password. The 7z format provides the option to encrypt the filenames of a 7z archive.

[Rowr14]

I haven't had any issues with save states, but I've set them up to save in a linked google drive folder so I can resume them from a different device without issue.

I think I unzipped for genesis and master system for the fact that kega couldn't deal with them zipped but haven't found many other problems otherwise

[sherylle1989]

I'm using 7zip for window 10 and for me, it has good functionality for compressing and uncompressing files...

[dark13]

On pc I use rar5 cd/dvd and a dynamic ramdisk to avoid too much stress on the hard disk (especially when testing stuff). With saturn and psx on retroarch you can compress multidisk games and use .m3u to use RA disk changer.

You can also consider windows NTFS compression, Circo says it's not that bad.

[Suhrvivor]

Last year I switched all my disc based collections to CHD and it's amazing! That format it's the best of both worlds. CHDs are highly compressed and most modern emulators can read them directly without needing any previous decompression.

I highly recommend using CHDs.

[justice999]

On 2/16/2019 at 4:42 AM, Suhrvivor said:

Last year I switched all my disc based collections to CHD and it's amazing! That format it's the best of both worlds. CHDs are highly compressed and most modern emulators can read them directly without needing any previous decompression.

I highly recommend using CHDs.

For what system?

[Suhrvivor]

@justice999 I use CHD for Playstation, 3DO, Sega CD, Saturn and Dreamcast. there are other systems out there that might support CHDs but I don't have them in my collection (PC Engine CD, Amiga CD32?, etc) so I can't really recommend them.