Ensure your external hard drive or USB drive is formatted to (for single ISO files over 4GB) or FAT32 (requires splitting the ISO using PS3 ISO Tools).
The trick, they said, was a special repack that used “lossless audio downsampling, texture re-encoding, and cutscene removal.” Sounded technical enough to be believable. Ps3 Iso Games Highly Compressed
Commonly used via 7-Zip , these provide high compression ratios by finding massive patterns in data. Ensure your external hard drive or USB drive