While USBUtil is a foundational tool for PS2 modding, it has known drawbacks: USB 1.1 Speeds
If you are setting up a PS2 and plan to play games via USB, USBUtil is a mandatory tool for any game larger than 4GB. However, for games under 4GB, simply placing the ISO in a "DVD" folder on your USB drive is often faster and more modern. Usbutil V2.2 Rev1.0-english.exe