The speed of your USB drive matters. While the PS2's port is slow, a cheap, slow flash drive can make things even worse. Use a known brand (SanDisk, Samsung, Kingston) with good random read speeds. A high-quality USB 2.0 or 3.0 drive (backward compatible) is ideal.
Fragged files or strict timing issues with the old USB 1.1 ports.
The benefits of using USBUtil v2.1 Ultimate are numerous: usbutil v21 ultimate for ps2 usb mode 2 link
The "Ultimate" version may refer to an unofficial mod with additional compatibility patches.
(often referred to as USBUtil 2.1 or 2.2) is the ultimate solution to this problem. It allows users to "slice" large ISO files, enabling games larger than 4GB to be installed on a FAT32-formatted USB drive, which is the necessary format for the PS2 to recognize it. The speed of your USB drive matters
running Open PS2 Loader (OPL) via FreeMcBoot (FMCB), FreeHDBoot, or a physical Modchip. Step-by-Step Guide: Converting Games with USB Mode 2 Link
is a Windows-based application designed to create, manage, and repair PS2 game images on USB drives. Unlike simple file copying, USBUtil creates a virtual file system recognized by the PS2 homebrew loaders. A high-quality USB 2
USBUtil elegantly solves this issue by automatically (commonly named ul.XXXXX.00 , ul.XXXXX.01 , etc.). It also creates a crucial index file named ul.cfg , which acts as a map for the loader on your PS2 to reassemble and read the game data correctly. Without a tool like USBUtil, you simply cannot play a single game larger than 4GB from a USB drive on your PS2.