P2 speed compared to hard drives & RAID 0.

[spikeman256]

I think I had read a message from Barry that said a key benefit to the "P2 workflow" isn't just to record to P2 cards and then offload them to other hard drives, but to edit from/to the P2 cards themselves.

1 - Did I understand that correctly?

2 - Will editing directly from/to a P2 card be any faster/slower than with most good hard drives?
(I see that PCMCIA/Cardbus slots have a maximum burst rate of 132 Mbytes/sec).

3 - I spoke to G-technology a few days ago and the rep strongly encouraged RAID 0 over a single hard drive...single hard drives providing around 40 MBytes/sec vs the 75 MBytes/sec with a RAID 0.

3a...can Final Cut Pro on a Mac edit just as quickly on a single 40MB/s drive as on a 75MB/s RAID 0 drive pair?

3b...can DVRACK HD on a PC stream to a 40MB/s single drive with no problems?


I see a benefit in streaming to/editing on RAID 0 for the speed (if that really is necessary) and then archiving on less expensive brand hard drives for cost savings.

Thx for input.

 

[bbalser]

You don't need RAID to edit DVCPRO-HD. I use regular old FW800 drives and never have a problem. RAID has advantages, but not RAID 0, IMHO.

Editing directly from a P2 card, I wouldn't do it. Then, when you're done, and you have to reuse the P2 card, poof, there goes your previous project. Dump the data to a hard drive to edit. Editing from a P2 is possible, but not practical.

 

[Barry_Green]

1 - Did I understand that correctly?

Yes. Editing from the cards blows away editing from a hard disk. The cards are faster in data transfer than any single hard disk, but the main advantage is in multi-stream stuff. Hard disks get slowed down by seek time, jumping between streams. The P2 cards have no seek time, no moving parts, so accessing any part of the card is instantaneous. So because of this, you can get six streams of 1080 off the card simultaneously. Look at G-Tech's big five-drive RAID systems and you'll see that even with a five-disk RAID they'll only guarantee three streams.

So that's one big benefit. The other perhaps even bigger benefit is -- you don't have to waste the time at the beginning of your project copying cards to a hard disk! You already have the footage on a superior edit media, why slow down your process copying it off of the superior media onto an inferior media?

(the answer, of course, is twofold: 1) because the card capacities are currently too small to make that workflow practical, and 2) the myopia of the NLE manufacturers who still refuse to allow native editing of MXF files). Once the last remaining NLE manufacturers get "on board" with MXF, and larger card capacities come out, you're going to see a big shift in the way people work with these cards. A bold prediction here, but I say that hard drive editing is headed the way of tape-to-tape editing; the "new workflow" will be: shoot to the cards, edit from the cards, finish your project, and then when you're done, archive the card contents off to something else like a hard disk or data tape or something.

But we're not there today. FCP users can't do it at all because FCP won't work with MXF files. We can execute this workflow in a limited capacity on Windows, but we're limited by card capacity. At the end of this year when you have 32GB cards out, and could have five of them loaded in a five-slot reader, you could have 400 minutes of footage on-line at once. That's almost enough to do an entire 90-minute feature film at a 4.5:1 ratio. Why would you want to waste hours copying those cards over to a slower edit media instead of just plugging 'em in, editing, and finishing your project? Copy to a slow archive media overnight when you're done, copy overnight for data redundancy purposes, whatever, but don't bog down your progress by copying to a slower media before you even start working! (this workflow would be for people who shoot all the footage for a project, and then edit the project to completion; obviously there will be others who use a different workflow, those who need to put the cards back into production before they're done editing, and for them they may find they still need to copy to hard disks at least until they could afford enough cards to maintain a fully integrated workflow).

2 - Will editing directly from/to a P2 card be any faster/slower than with most good hard drives?

Always faster, for two reasons: 1) you didn't have to spend all that time at the front of your project copying the cards to the hard disk! and 2) the elimination of seek time, as mentioned above.

Again, this is not really practical right now, with the limited card sizes available today (and with the incomplete MXF implementation of FCP). I'm talking about where this workflow is HEADED, not where it IS TODAY.

3 - I spoke to G-technology a few days ago and the rep strongly encouraged RAID 0 over a single hard drive...single hard drives providing around 40 MBytes/sec vs the 75 MBytes/sec with a RAID 0.

Of course he did; G-tech sells RAIDs. But DVCPRO-HD edits fine from single drives. RAID0 will be faster of course, and I bought a G-RAID 500GB, but don't think that you NEED something like that (unless you're going to be doing a lot of multiple-stream editing from a hard disk.)

3b...can DVRACK HD on a PC stream to a 40MB/s single drive with no problems?

Yes.

 

[THoff]

I would never edit on RAID0 (or keep valuable data on it) because it increases the chance of data loss because you have a larger number of potential points of failure.

If you are investing in hardware anyway, use a higher form of RAID that provides both data protection and increased performance.

 

[eLeventy]

But we're not there today.

Well, we are! For news, we have 7 mobile editing camera crew vans. The crews shoot on SPX-900's ( SD) on P2, stick the cards in our 5-slot readers, edit directly from the cards( Avid NewsCutters) without copying to drives first. Then voice-overs, and transmit using COFDM wireless transmitters, also built into the vans, to the broadcast centre. Then, we're of to the next story. In the evening, 'back at base', we insert the cards into one of four workstations in the garage, and all cards are automatically ingested into the archive.

This is all done by two-man crews, covering camera, sound, editing, live positions,...

 

[bbalser]

It must be nice to work for a company that has that much money...

 

[Barry_Green]

Well, we are! For news, we have 7 mobile editing camera crew vans. The crews shoot on SPX-900's ( SD) on P2, stick the cards in our 5-slot readers, edit directly from the cards( Avid NewsCutters) without copying to drives first. Then voice-overs, and transmit using COFDM wireless transmitters, also built into the vans, to the broadcast centre. Then, we're of to the next story. In the evening, 'back at base', we insert the cards into one of four workstations in the garage, and all cards are automatically ingested into the archive.

This is all done by two-man crews, covering camera, sound, editing, live positions,...

That's exactly what I meant, yes. That's what the workflow is designed for. For longer-form projects it's not so practical for smaller-budget guys YET, but it'll get there. For news crews it's ideal.

What you're describing is exactly the way it's going to go. The whole "hard disk" thing is a temporary patch, a concession to market realities, but it's certainly not preferable!