dantm

Quick question: firewire

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Hi, does anybody know the firewire CPU utilization for a CD/CD-RW? How does that compare to SCSI?

Also what's the maximum cable length for a firewire device?

Thanks,

/Dan

PS. Just for the curious, I am thinking whether to get rid of my internal SCSI CDRW and go with a Firewire external one.

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I would estimate about 3%. Compares fine to SCSI. Max length is 5m, tho granitedigital claim theirs can do 10m.

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1. Firewire support is embedded into OS (Win2K/XP). Other features & resulting utilization depends on the driver installed (if any). Utilization shd be in the range of SCSI (approx. 3-5%).

2. Performance shd be close to SCSI, potentially better depending on implementation. This is particularly true for AV applications as IEEE 1394 supports guaranteed constant bandwidth for audio and video applications that require constant real-time transfer rates (called isochronous data transfers).

3. Per IEEE 1394 spec, at transfer rate of 400 (Mbps) & support for up to 63 devices, then maximum cable length is 14' (4.5 meters). It has been done (out of spec tho) at up to 100 Mbit/sec over more than 20 meters using standard cable, with some combination of thicker cable & lowered transmission possible inbetween.

For Firewire networking, repeaters can be placed between 15 ft cables for a maximum distance of 237 feet (72 m).

:ph34r:

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Firewire is serial SCSI, and has about the same CPU as parallel ScSI. I doubt the diff between SCSI and IDE is over 1% too.

A Firewire CD-RW is an IDE CD-RW with a bridge chip to convert IDE to Firewire. Unless your SCSI drive is failing I would keep it.

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Ok, this is good enough information...thanks a lot guys...

One more question though...or more like a suggestion.

Right now I have an all SCSI computer, consisting of 2 Ultra160 drives, a CD-RW (50 pin) and a CD-ROM (50 pin). I have two cards, one a LSI Ultra160 for the hard drives and an old 50 pin PCI card for the CD-RW and CD-ROM.

The computer is being kept in a closet so that I don't have any noise in my living room. Wires run through a wall to a LCD display and keyboard/mouse combo.

Basically what I'm trying to do is get an external drive close to my LCD/keyboard, so I don't have to go to the closet all the time to change disks.

So what I can do is:

1) external SCSI drive to be run off the old 50-pin SCSI card (I might not have enough length to meet the requirements)

2) external Firewire, dump the old SCSI card, and the internal CD/CD-RW drives, and get Firewire CD-RW.

What do you guys suggest?

Thanks,

/Dan

pS> one more question -- if I only have a Firewire CD drive, how can I install software since the drivers for the card are not loaded when the computer hard drive is blank????

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one more question -- if I only have a Firewire CD drive, how can I install software since the drivers for the card are not loaded when the computer hard drive is blank????[/b]

You can't. No PC mobo that I know of supports booting from a FW drive. Though I believe Ghost has drivers for USB/FW devices.

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one more question -- if I only have a Firewire CD drive, how can I install software since the drivers for the card are not loaded when the computer hard drive is blank????[/b]

You can't. No PC mobo that I know of supports booting from a FW drive. Though I believe Ghost has drivers for USB/FW devices.

Plus, You'd need the OS support at boot also.

Jan

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There’re two things that puzzle me.

1. Is there a reason you can't /won't / don't want to run both an internal and an external CDRW?

2. Surely, once the Os and firewire burner are installed you'd be able to install any other software from an external burner?

Because in your situation I'd be inclined to simply add whichever external writer would stretch to the desk.

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Yes you are right -- I can run both internal and external...I was thinking from the perspective to minimize the internal SCSI cards (Going firewire would have me dump the old 50 pin card). I guess I can keep that and just have an external drive on top like you mentioned.

Thanks,

/Dan

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