Firewire (480Mbps) to USB 2.0 conversion?

GeoffCampbell wrote on 12/20/2005, 10:50 AM
I was told that IEEE 1394, Firewire, and I-Link all transfer at 480Mbps. USB 2.0 transfers at 400Mbps. I know that there's new Firewire 800 out there. My question is, if I buy a Firewire (480Mbps) to USB 2.0 converter cable, or plug, for my Notebook, will the 80Mbps difference make a significent difference in transferring my
raw video?

Thanks for any help, suggestions, or opinions. (Cost is a factor)

Happy Holidays to all.

Best Wishes,
Tony

Comments

p@mast3rs wrote on 12/20/2005, 10:57 AM
The data rates you speak of are PEAK data rates not sustained. That sai, USB fluxuates with its data rates and firewire provides a more consistent data rate when transferring. I dont USB 1 or 2 for any storage needs. Just not reliable and quick enough for me. best to stick with firewire.
John_Cline wrote on 12/20/2005, 11:05 AM
Firewire and iLink are names for the IEEE-1394 serial interface. "Firewire" is a tradename coined by Apple, "iLink" is Sony's name for IEEE-1394. IEEE-1394 transfers at 400Mbps (or in the case of IEEE-1394b it's 800 Mbps.) USB 2.0 transfers at 480Mbps, but it requires a lot of CPU intervention, IEEE-1394 does not, which actually makes it faster in the real world.

To my knowledge, there is no such thing as a IEEE-1394 to USB 2.0 converter cable. Generally speaking, DV camcorders will only transfer full-resolution, full-quality video via the IEEE-1394 interface. The USB interface on DV camcorders is only used to transferring still images and low-resolution "webcam" quality video. If your notebook computer has a Firewire port, you're all set, otherwise you will need to get a Firewire card to plug into the Cardbus slot. These can be had for around $50.

As far as external hard drives are concerned, both USB2 and Firewire work well, but Firewire works better.

John
Guy Bruner wrote on 12/20/2005, 11:46 AM
Plus, DV is 25 Mbps and it transfers at that rate. There is no way to speed it up. So, it doesn't matter, bitrate wise, which is faster.
busterkeaton wrote on 12/20/2005, 12:49 PM
As far as external hard drives are concerned, both USB2 and Firewire work well, but Firewire works better.

John

To elaborate on that, USB transfers require some CPU power while firewire does not. So if you have a slower computer and more than one USB drive, you could experience some lagging as all this has to go through your motherboard's bus.
Chilivonhaus wrote on 12/20/2005, 1:06 PM
As an experiment, I have successfully captured DV footage from a camera via USB 2.0 connection, into a USB 2.0 external hardrive through a laptop. No dropped frames, everything appeared OK.

I practice however (heeding the wisdom of forums like this one) I always use IEEE 1394 connection to capture and transfer DV footage to avoid any potential problems.
RBartlett wrote on 12/21/2005, 7:08 AM
There is a firewire-DV to USB2 converter - however it converts to MPEG-2 on the way, it is a smarter cable than we would rather it be. I actually like the driver side of firewire compared to USB2 (better use of the CPU in almost all cases) - but think that USB2 is more foolproof for PlugAndPlay - due to the lack of adherence to circuit protection on most firewire implementations - plug and break in other words. I recommend connecting firewire devices with the power off, just as per the instructions for parallel port printers. There are few devices that use self resetting fuses - they blow diodes instead. Not always - but when these firewire devices are >$500 a piece, sometimes >$50000 - this isn't pretty even with accidental damage insurance. Rant over.

The camera Firewire->USB2 host cable is fairly useless within this discussion but here is a link anyway (useless because we avoid editing MPEG-2 when DV is available with a hoop jump or two):
http://www.pixela-1.com/captycable/
GeoffCampbell wrote on 12/21/2005, 9:07 AM
To: RBartlett:

Thanks for taking the time to answer my post.

You were very kind in ding so.

Have a great Holiay Season.

Best Wishes,
Tony M.