Hi, You'll get only USB1.1 performance (i.e. dismal) unless you add a USB2 PCI card. These can be had quite cheaply (e.g. US$20), but I don't know how well they integrate into the rest of the OS (e.g. whether there are sleep issues). Perhaps someone will recommend a card? Regards, Charles > >From: "O'Brien" <obgraph at hiwaay.net> > > >Can I use a USB2 external HD with an 800mHz Quicksilver / OSX.4.8? > >Thanks. > > -- "The question is", said Alice, "whether you can make words mean so many different things." "The question is," said Humpty Dumpty, "which is to be master -that's all."