IDE - Firewire - USB2

OpChiasm wrote on 2/3/2003, 9:15 AM

Thanks in advance for any information. Apologies in advance if this has been covered in the past, but I didn't find anything when I searched. I did read through the "Is it better to capture video on seperate (sic) drive" thread, but didn't see anything.

Assuming the use of a separate drive dedicated to video capture (and all else being equal, ie, manufacturer, rpm, etc.), as a rule, is it "better" (and I'm not even sure what I mean by that) to capture to IDE, Firewire, or USB2.

Due to physical constraints, I was forced to go with an external drive and was swayed by the 480 vs 400 thing, so I got a USB2 drive (LaCie, actually a Maxtor in a LaCie uniform). I haven't had any problems, but it seems like more people use firewire.

Thanks again.

Comments

mikkie wrote on 2/3/2003, 10:17 AM

I *think* that currently none of the 3 will fully utilize the fastest drive, & IMO, which is the fastest way to access your drive has a bit to do with your motherboard & if you have to add a card for firewire or USB2 support. Firewire vs USB 2 I'd pick Firewire if price were not a factor & both were native to the M/Board.

An example of sorts, I measured drive performance on a new drive hooked up to an IDE channel on the M/Board & on a Maxtor/promise IDE card. The card allowed the drive to use it's UDMA 6 capabilities, but it is faster hooked to the M/Board at UDMA 5. One factor is that it would be hard to find a system that will fully utilize udma6, and another is that going through the pci card bus, the bandwidth for data reaching the drive is restricted.

mike

OpChiasm wrote on 2/3/2003, 10:38 AM

Thanks very much for that information. I didn't think about factoring in the PCI interface.

As I said, I was forced to go external. My MB (Intel 845E something or other) has native USB2, but I have a PCI Firewire card. Given the fact that USB2 is native, I probably (thiugh unwittingly) made the right choice.

Thanks again for the information.

JackHughs wrote on 2/3/2003, 12:15 PM

I don't believe that drive speed (data transfer rate) is the primary consideration in choosing the best configuratation for capture/print-to-tape. DV moves at a 3.6 mB/sec - well within the sustained transfer rate of USB2, Firewire, or UDMA Mode 2 (ATA/33). The primary concern is that the DV data stream not be interrupted for any reason.

Theoretically, Firewire should be the best connection because it is peer-to-peer. If you have a camcorder attached to one port of a Firewire bus and a harddrive attached to another port (not daisy-chained), then data should flow directly over the Firewire bus from one device to the other. Whether the theory holds up in real life, I don't know.

A Firewire/USB2 is definitely not peer-to-peer. You have the capture device (camcorder), the Firewire controller, the PCI bus, the USB2 controller, a USB2/IDE bridge in the storage device enclosure, and the storage device itself.

Basically, if you capture to an intrnal IDE drive, the data comes off the PCI bus and on to the IDE device. With USB2, the data is still going to an IDE device, but it is routed through all those other widgets in the USB2 path.

So, I think the common wisdom runs something like this.

The very best chance for successful capture/print-to-tape has your capture drive connected to an independent IDE channel. That is, it is the one and only device on that channel.

When using external drives, make sure that the drive and the camcorder are connected to seperate ports and all other devices are disconnected. This gets a little tough on systems with only one on-board USB2 controller and the user has dedicated one port to a USB1.1 mouse and/or keyboard.

Do not daisy-chain a camcorder and a Firewire drive. It might work, it might not. Worse, it might work intermittantly.

All of the above information has been "mined" from this forum and other DV websites. If any of it is incorrect, I would like to know.

JackHughs

Kevmiami wrote on 2/4/2003, 1:08 PM

Thank you for taking time to share; very helpful info!!

deef wrote on 2/6/2003, 1:14 AM

Thanks JackHughs for providing the good info.

Agreed on the Daisy-chaining issue, from my experience in developing/testing Video Capture, I find a much better chance of success if using a Sony DV device. Here's a setup I use often @ SOFO:

notebook (on-board OHCI 1394) -> AcomData hd -> Western Digital hd -> Sony TRV11

It seems the DV chipset on Canons/JVCs/others don't properly handle simultaneous command/data xfers on the 1394 bus. Besides making DV daisy-chaining unusable, these devices also cause the DV timecode UI updating to "catch" frequently.

Thanks!

jldpc wrote on 2/6/2003, 3:48 AM

I use an Adaptec Firewire card (3 ports: for my Sony DCR-VX1000, and the Canopus ADVC-100, and the WD 120gb external. The Audigy sound card firewire port is not used.

I capture and edit on the 7200rpm WD; but I do render to one of my three 15000rpm Seagate SCSI's. I use NT file system, not FAT32.

No problems, except an intermittent one.

Sometimes when capturing the sound gets out of phase at the pc level. Its the burden on the system. Presntly using a Piv2000. Am upgradeing to a Piv3.06 to see if it fixes the problem.