Problem with FW daisy-chaining and drive speeds!? Advice needed!

[Fallinangel]

Hi,

I have three LaCie D2 Quadra external hard drives, which are daisy-chained to each other and than connected to the FW800-port of my iMac:

iMac
^
^
HD 1 - 1000 GB (iTunes Library)
^
HD 2 - 1000 GB (Backup of HD 1)
^
HD 3 - 500 GB (2 Partitions: 1. System Backup, 2. Misc Files)​

I've recently added the 3rd hard drive and now the drive speeds have dropped considerably!?
Importing music into iTunes (copying to "HD 1"), editing music tags on the same drive and/or adding files to the "HD 3" drive takes much longer than before!

"HD 1" is quite frequently used for music playback and video watching.
"HD 2" is used once a day during the night for backup purposes only.
"HD 3" is regularly used. The System Backup partition is rarely touched, but the Misc Files partition is used a lot!

Any idea why the construct has become so slow?
Would it solve the issue, if I would take one drive off from the daisy-chain, an connect it to another port (USB or FW400)?

Thanks.

 

[BlueRevolution]

Would it solve the issue, if I would take one drive off from the daisy-chain, an connect it to another port (USB or FW400)?

Yes.

 

[Consultant]

Open disk utility, verify disk on all drives.

If you turn off drives, you need to wait for drives to spin down after ejecting (10 seconds or so) before powering off.

-----

Perhaps the second port on HD2 (that you started using with HD3) is messed up? Or new drive is messed up?

It shouldn't slow down with daisy chaining if nothing is happening.

 

[JustGretchen]

I have daisy chained 4 FW400 drives together w/o any issues before. They were all different brands too.

It is possible for the transfer rates to take a performance hit if more than 1 drive is being accessed at the same time if they are all on the same initial port on the mac.

I would suggest, if you have the FW400 port available, use it for your HD2 backup drive. Yeah it'll be slower overall, but faster than USB2.0 and since you don't use it except to make a backup every night then who cares right?

FYI, a FW bus is claimed to be able to handle 63 devices i believe.