How does daisy-chaining of external drives work?

[c-t]

I have an iMac with one FW800 port and one FW400 port.

I already have a LaCie Rugged drive with one FW800 port and one FW400 port. I have it connected to my iMac's FW800 port.

Now, I want to connect a second external drive to my iMac. I'm thinking about buying WD My Passport Studio with two FW800 ports.

My question is: There are two choices I can take in order to connect those drives to my iMac:

1. Connect the LaCie to the iMac's FW400 port and connect the new WD to the iMac's FW800 port.
2. Connect the new WD to the iMac's FW800 port, and daisy-chain the LaCie to the WD's remaining FW800 port.

My question is: Which option should I choose? I guess option 2 would be better, since both are on the FW800 bus. However, since there are two drives on the same bus, doesn't it slow down the entire bus?

 

[simsaladimbamba]

1. Connect the LaCie to the iMac's FW400 port and connect the new WD to the iMac's FW800 port.
2. Connect the new WD to the iMac's FW800 port, and daisy-chain the LaCie to the WD's remaining FW800 port.

My question is: Which option should I choose? I guess option 2 would be better, since both are on the FW800 bus. However, since there are two drives on the same bus, doesn't it slow down the entire bus?

Option 2 will work just fine, I currently have three HDDs connected to my iMac that way, all with FW800 ports and I get FW800 speeds too.

 

[c-t]

Option 2 will work just fine, I currently have three HDDs connected to my iMac that way, all with FW800 ports and I get FW800 speeds too.

Okay, thanks. What if you're transferring files from all three drives at once to your Mac (or between one another)? Do things slow down?

 

[simsaladimbamba]

Okay, thanks. What if you're transferring files from all three drives at once to your Mac (or between one another)? Do things slow down?

If I copy from three HDDs via one interface (FW800 in this case) to one HDD, I will be limited by the interface and the one HDD, which has to write three streams onto it.
If I copy from on external HDD to another external HDD via FW800, I get FW800 speeds.