The FAT32 file system has a critical limitation: no single file can be larger than 4GB. Since many PS3 games exceed this (e.g., God of War 3 is ~33GB), you cannot place a full ISO on a FAT32 USB drive.
Use a client like FileZilla to transfer the files directly to dev_hdd0/PS3ISO on your console's internal hard drive. ps3 iso tools 4.89
This "Swiss Army knife" for the PS3 scene offers several essential functions: The FAT32 file system has a critical limitation:
: Convert entire game archives or single folders into ISOs compatible with managers like webMAN MOD . This "Swiss Army knife" for the PS3 scene
: Useful if you only need to break down large files without re-encoding the entire ISO. 4GB Files - ConsoleMods Wiki
You can select an entire directory of games to convert them all at once. How to Use PS3 ISO Tools on Firmware 4.89