[redalert51]

I just bought a Lacie 120gb usb hd for some it is only connects via a powered
hub but is not recognised when connected directly by my G4
onboard USB ?

[mduell]

Sounds like the ports on your G4 aren't providing enough power. Did the drive come with a second USB plug? You should plug that in; the hub may be 'doing you a favor' by violating the USB spec for max power.

[EndlessMac]

That's just one of the reasons why I don't like USB powered external hard drives. Sometimes the USB port doesn't provide enough power to operate something that requires so much power like a hard drive. Firewire is faster anyway so I usually like getting one that has Firewire and an external power source. Mduell has it right. You'll probably need to use two USB ports in order to power your hard drive.

[mduell]

The USB power spec says 0.5A at 5V max (2.5W); most 2.5" hard drives have a peak power demand of 2.4-2.6W, so it's close and depends a lot on the chipsets. If the PowerMac is only supplying 2.3W, or the hub is supplying 2.7W, then one will work and the other won't.
Fortunately most enclosures come with the extra USB lead (maybe even with passthrough so you don't lose the ability to use that port for another device), and USB ports are a dime a dozen on modern computers.

[alligator]

What firewire external drives to people recommend?

[EndlessMac]

Originally Posted by mduell 

USB ports are a dime a dozen on modern computers.

They are but I've noticed that my Firewire drive is twice as fast as my USB drive so no more USB drives for me.

Originally Posted by alligator 

What firewire external drives to people recommend?

I have two Seagate drives but there are several other brands out there. I don't have experience with the other brands so I can't comment on how reliable they are.