Can enternal HD only daisy chain with FW?

[Bertmg]

I heard that for external HD to be able to daisy chain and maybe convert into different RAIDs, the Hard drives must be connected to each other and to the laptop all with the same type of connections format.

So

LAPTOP HD1 HD2
FW 400/800 + FW 400/800 + FW 400/800 = Yes
USB + FW 400/800 + FW 400/800 = No
ESATA + FW 400/800 + FW 400/800 = No
ESATA + USB2 + USB2 = No

Is this true?

 

[spinnerlys]

As Firewire, S-ATA and USB are different buses, you can't daisy chain hard drives mixed via those buses.

And only Firewire is able to daisy chain external devices, the other two don't have that option.

With Firewire you'll be able to chain up to 63 devices together, but the device with the lowest speed (FW 400 or FW 800) will determine the speed of all the other devices.
In other words, one FW 400 device in a chain with 62 other FW 800 devices will make the chain only work at the maximum speed FW 400 provides.


So in short: It is true.

 

[gr8tfly]

As Firewire, S-ATA and USB are different buses, you can't daisy chain hard drives mixed via those buses.

And only Firewire is able to daisy chain external devices, the other two don't have that option.

With Firewire you'll be able to chain up to 63 devices together, but the device with the lowest speed (FW 400 or FW 800) will determine the speed of all the other devices.
In other words, one FW 400 device in a chain with 62 other FW 800 devices will make the chain only work at the maximum speed FW 400 provides.


So in short: It is true.

Just a note on mixed 800/400:

With mixed FW800 & FW400, and FW800 had the head of the chain, I get full FW800 speeds (or, at least the unsaturated HD transfer rate which is much higher than FW400). I have 3 FW800 HDs, followed by 3 FW400 devices (2 HD, one burner).

 

[spinnerlys]

Just a note on mixed 800/400:

With mixed FW800 & FW400, and FW800 had the head of the chain, I get full FW800 speeds (or, at least the unsaturated HD transfer rate which is much higher than FW400). I have 3 FW800 HDs, followed by 3 FW400 devices (2 HD, one burner).

It's good to know to put the FW 800 ahead of the others. I will try it sometime.
Thanks for the hint.