write speed to usb2 hard disc

Constantly repeated advice here is to use FireWire, and NOT USB (1 or 2) for video.

Your experience seems to support this. Sorry.

Yep, firewire, although apparently slower than USB2, is actually more reliable for DV throughput.

However, I'm using a LaCie 250G drive on my Vaio laptop with the USB2 connection, and it's fine for video. So I state with 100% confidence that you never can tell what's going to work on any particular machine. For example, I recently grabbed some DV footage into a Dell Centrino laptop (1.7G), onto it's internal drive with no problem, but I can't play it back through the same firewire port because it outputs at only about 8 frames/second. The Vaio (2.8) P4 has no problem, nor does my old Dell P4 desktop (1.8G).

Yes thanks for that.
I've been to a friends' this evening who has recently purchased an amd 3200+ etc etc and of course with usb2 built into the motherboard. I copied a 550 MByte .avi to my usb2 hard disc from his pc and it took 38 seconds. Well I reckon thats about 14.5 MBytes/sec, over twice as fast as my amd 1900.
Not that fast really, tho fast enough for comcorder download me thinks. Of course theres a lot to consider, pci bus speed verses built in motherboard bus speed, processor speed, cache size and so on.
I read PC Pro's test on external hard discs and they got terrific results, but then they set up special conditions, for example they used ramdisc as a source.
My PC has udma 133 (or was it 33, will have to check) as opposed to modern sata drives.
Still all is not lost, I'll just have to get the raw avi on to the internal h/d and then transfer to usb h/d. I've no idea what will happen when I try to edit with the usb as the source!! I've got that to look forward to.
Actually would be quite interesting to see what results other board members get when copying a largish file from internal hd to external. We could get results in MB/s or GB/hour.
What do you think???
cheers
Dave H

check that the drive is set up for 'performance' and not 'quick removal'.

i'm up to my eyes at the moment , but there are other hints in previous posts by myself etc as to how to improve things.

a quick search may find others ...... ok back to controlling the plenary session at the conference........

USB2/s plenty fast for DV (only needs 25Mb/s, about 3MBytes/sec) but is not guaranteed to give uninterupted data flow, it's a bus. Data travels in packets, several devices can use the same bus at the same time, data's packetted and interleaved so can get interfered with.

Firewire's spec'd at 400Mb/s as a bus system, but far more importantly, it's much less prone to interruption because it sets itself up as a peer-to-peer conference when transferring data, so it's far less prone to drop data.

Thanks chaps, yes I suppose I was hoping it was like the SCSI cenario; at one time that was the ONLY disc type to have but now almost any built in disc is fast enough - (how times change), and that usb2 would equal firewire.
Gary - twin xeons!! gulp well I guess you dont have speed problems, will you be lining up for the new amd/ intel dual processors, and when motherboards become available for twin dual processors - phew!!
Regards
Dave H

Dozey Dave,

I have used a usb2 hard disk on several occasions without any problems, infact, I have just bought another one last week, I certainly wouldn't have done that if I wthought I couldn't successfully download my dv tapes to it and use it as an editing drive.

I think you should check that your usb2 card is correctly installed/functioning rrectly/drivers installed as the performance you are getting seems more like usb1 performance.

Cheers John

Indeed, I have a LaCie box that I connect as USB2, and use the Vaio laptop's firewire port to connect to a Walkman. It works beautifully. But you can't guarantee it on any PC (the exact same system on a Centrino laptop will capture perfectly, but can't play out at sensible speed). Firewire's more reliable for constant-rate data than USB.

Mine are slow twin xeons. ( oh and that is work kit , my personal fastest pc is a p4 2A Ghz chip. )

to use edius with hdv footage and nx card as demoed at videoforum , it is suggested ( yeah right ) that you need a minimum of twin xeon 3.0Ghz.

Basically you stick the fastest you can afford or is available into the box and live with it.

Oh and even with twin xeons , i can make my system need to think for a while.

It just does most things in realtime , and when it does need to render , it isn't an all day or night job.

some people have said that when you have an external hard drive connected into the same firewire card as the camcorder they can interfere with other when loading data from a dv device.

Is this true and if so how do you get around it?

Paul

You may be OK, you may not. I usually use

- a DV deck/camcorder
- a FW external hard drive and
- a FW port on the computer

all daisy chained together, and it captures from the deck to the drive completely reliably. YMMV. Try it and see.

If it doesn't work, your next option is to connect the DV deck/camcorder to one FW port on the computer, and the external FW drive to another (assuming you have two FW ports on your computer.)

I have experienced it, but on same connection , not same card.

I connected the hard-drive to one firewire connector.
I connected the camera to a different firewire connector.

Snap!

All on the same card, thats what I did,
I have another firewire card I can fit this to the coputer and try it.

"all daisy chained together, and it captures from the deck to the drive completely reliably. YMMV. Try it and see."

What do you mean daisy chained, and is your DV deck/camcorder connected into the same firewire card as the external hard drive?

daisy chained = camera to firewire input on external drive , second firewire connector on drive out to pc.

like daisy's that little girls connect one to the other by slitting the stem and feeding the next stem thru so that head is at split and proceeds all the way round the necklace/bracelet etc.

I've had no problem with a daisy chain of 2 external drives and a camcorder on the end.

OK.........this is what I mean by daisy chained:

My external hard drive has TWO 6pin FW connectors on the back (call them A and B), so I use two cables:

- one 6pin-6pin from the computer to the ext. HD FW socket A
- one 6pin-4pin from ext. HD FW socket B to the DV deck/camcorder.

so, "yes" to your second question, but via the external HD drive - see above.

Correct, excpet that I have a second hard drive in the chain as well.

That works fine now, thank you mooblie.

Paul