What USB type does the CECHA have

I'm looking into booting PS2 games off an External HDD, since I don't have enough on my internal drive and I have the maximum size HDD (1TB according to my research). Apparently booting off USB using OPL does work, however one of the issues with OPL for the original PS2 was USB 1.1 speeds, USB 1.1 was too slow and FMV's and other games would have issues. But the PS3 should have more modern USB versions like USB 2.0 shouldn't it? Would those be faster and thus avoid these sorts of issues? Or would the PS3 throttle the ports back to 1.1 speeds when in PS2 mode? Can anybody help me? I'm looking all over for solutions for extra storage for PS3, PS2, and PS1 games but I'm grasping at straws here? It wouldn't be such a big deal if the PS3 supported 4TB internal drives, or if people could give modern, non-conflicting answers.