Yes, a firewire HDD would not have 'AS' diminished performance. But you have to have the right speed of firewire (Firewire 800 or Firewire B) which is Firewire 800. It's 800 Megabits/second so it's the equivalent of an IDE drive in speed. If you do have the new technology E-SATA (External SATA), I would recommend using that if you want to game. But most normal PC's don't have E-SATA as it is quite expensive and E-SATA drives are few and far. So Firewire 800 would be your best bet, but it would provide an unpleasant bottleneck in today's games. Even then it's not worth it as SATA drives are so much cheaper and faster.