iPod USB2 Details

[jettredmont]

Originally posted by eric_n_dfw
I agree about the transfer speed - Firewire400 is faster sustained (where it counts) but USB2 is no slackard either. The power situation, though, still intregues me. Is what you quoted for the whole bus? If I had a mouse, keyboard and bus powered hard drive all on the same USB2 hub, would the drive (or iPod in this case) suck all the power down, leaving the mouse and keyboard high and dry?

USB power is provided by the hub (asuming it is "self-powered") or by the root port on the computer (assuming your hub is "bus-powered".

If you are going through a "self-powered" hub, the 2.5W of power is supplied to each outgoing port. You would only "share" that 2.5W if your devices are connected through a bus-powered hub (which would be an option with most hubs if they're away from an AC outlet, and is most common in USB keyboards that have a fe "bonus" ports for your mouse and whatever).

So, the answer is "Porbably no, but maybe yes".

 

[jettredmont]

Originally posted by g4cube
On a related note, do you realize that most DV camcorders only operate at 100Mbps or 200Mbps max data rate on a FW400 bus? May actually be noted on the camcorder as S100 or S200.

Hmm. I have a far-from-top-of-the-line Sony, and it states in the manual that it supports 400Mbps, 200Mbps, and 100Mbps operation modes on 1394a. Which brands limit themselves to the 200Mbps data rate, so I know to avoid them if/when I get a new camera?

 

[g4cube]

RE: slow FireWire Camcorders

Early iLink camcorders, like my DCR-PC1.

Some of the first VAIO computers with built-in iLink. (laptops and desktops)

DVMC-DA1 Sony iLink-analogAV Media Converter

For more esoteric, google "s100 iLink" or "s200 iLink"

The fact that these are slower devices does not hinder their actual performance. they "just work".

 

[g4cube]

Originally posted by jettredmont
1: Can you provide a link to a USB-powered drive (hard-drive, not flash, of course!)? I haven't seen one. I've seen a USB-powered scanner (which is a neat trick), but never a USB-powered hard drive.

Just google "bus powered HD USB2" for a few links. When I was evaluating a new case design, was surprised that several vendors of cases offered USB2 powered HD capabilities. Note well: won't work on all computers; and won't work with all drives.

The reason why they work? Some vendors deliver more than 500ma, as Apple does on some desktops (to drive their USB speakers).

As for charging rates, of course. Additionally, though, Apple does not guarantee 15W on all their FireWire ports. As has been noted elsewhere, some computers are as low as 6W or 8W shared.

So, yes, FireWire "can" provide more power than USB, it is not required, nor always available.

Don't get me wrong - I am not an Apple basher (I am a shareholder), but I cannot let misinformation get propagated.

Both USB2 and FireWire get the job done. It's just that FireWire is better in some aspects.

On the otherhand, USB is better, since it is available on 100% of the personal computers sold today (OK perhaps 99.9%), but FireWire is a bit less (insert your favorite grinning emoticon here).

All the PC's in my home have both FireWire and USB capability.