[phi]

Hey all,

I would like to seek your advice on the above.

Scenario 1:
I daisy-chain 4 1-Drive FireWire400 enclosures. I can only use FireWire400 as that is the only option available on my 20’ iMac. USB2 as I have learnt is a poorer alternative. As I foresee that I would be transferring files often between these external drives, I wish that file transfer speeds between these enclosures would be fast.

I have read that FireWire communicates via node-to-node. Therefore, in a daisy-chain of the 4 drives. If I were to transfer a 1GB file from one external drive to the other, it would enjoy the theoretical 400mbps?

Scenario 2:
I purchase a single 4-Drive enclosure that has 4 bays in which I slot my HDD in.The drives could be SATA/PATA but it does not matter since the bottleneck is the FW400 speed right?

This enclosure is connected to my Mac via a single FW400 cable. Suppose I transfer a 1GB file in the aforementioned scenario, between drive to drive. Does the node-to-node principle still apply? That is, is the file is transferred directly from drive to drive? Or, is it transferred first to the internal hard disk drive on the iMac?
If so, would that mean that the file transfer speed would be slower since it involves simultaneously reading/writing from the iMac which would theoretically halve the transfer speed to 240mbps?

I could be uttering nonsense; if so, I do seek your clarification.Thanks!

[phi]

Any help would be appreciated. Thanks!

[indigoimac]

I really have no idea about the node to node thing, but I'm pretty sure(have a 2drive FW enclosure) that the data goes from drive to drive and not to the iMac's internal disks 1st.

[mduell]

1. No. The data would go from one drive, to your iMac, and back to the other drive. The "peer-to-peer" logical configuration of the Firewire bus doesn't mean it will transfer directly from drive to drive; think about the same situation, but without the iMac; can you move files from one drive to another? Or a FW camcorder attached to a FW harddrive, etc.

2. Depends on the enclosure. Standard consumer-grade stuff? No. High-end enterprise-grade stuff? Probably.

edit: I suppose the answer to 2 is probably also the answer to 1. There may be some high-end enclosures that allow direct transfer from enclosure to enclosure.

[phi]

Originally Posted by mduell 

1. No. The data would go from one drive, to your iMac, and back to the other drive. The "peer-to-peer" logical configuration of the Firewire bus doesn't mean it will transfer directly from drive to drive; think about the same situation, but without the iMac; can you move files from one drive to another? Or a FW camcorder attached to a FW harddrive, etc.

2. Depends on the enclosure. Standard consumer-grade stuff? No. High-end enterprise-grade stuff? Probably.

edit: I suppose the answer to 2 is probably also the answer to 1. There may be some high-end enclosures that allow direct transfer from enclosure to enclosure.

Yea, I'm just at the consumer-level stuff.

In that case, does that mean regardless of either solution, file transfer speed would be halved to ~240mbps if I were to transfer from external drive to external drive?

[phi]

Any help would be appreciated. Thanks!