Multiple FW400/800 devices on Macbook Pro

[bensonhedges]

Hi everyone,

I've got a last revision Macbook Pro (2.4ghz bought last March), and I've got a few little questions about some purchases I'm planning on making. My plan is to purchase two 1TB WD Mybook Studio drives and daisychain them from the single FW800 port on my MBP. I'm going to use them to back up important stuff, and they'll be mirroring each other to offer some redundancy.

I have a MOTU 828 mk3 audio interface plugged into my FW400 port, which I use for recording and making music in Logic Pro.

Now, the questions...

1) Am I right in saying I can daisychain the two drives from a single port like this?

2) Do the FW400 and FW800 ports share the same bus in the MBP? Are there any bandwidth issues I should be aware of? i.e. will accessing a file on the external HDD cause the audio to drop out on the audio interface?

3) Will using a FW400 device at the same time as a FW800 device cause the FW800 device to drop to FW400 speeds?

Any advice on this matter would be greatly appreciated!

 

[Teej guy]

I second the question!

 

[J the Ninja]

1. Yes, you can do it.

2 and 3: Ok, first, there is only 1 FW bus in the MBP, so all 3 devices are going to be sharing one link. And yes, putting a FW400 device into the group will drop back the whole system to FW400, so you'd have all 3 devices on one FW400 bus. Whether or not that actually causes problems for you is going to depend on what you are doing at the time.

 

[Sweetfeld28]

I think this might answer your questions?

Appleinsider Forum

 

[bensonhedges]

Thanks for the replies guys.

I kinda figured that I'd lose my FW800 speeds if I was hoping to use a FW400 device too. Well, it's not the end of the world, because my MOTU interface isn't on the whole time...it's often off, so i guess i'll still get to use my disks at FW800 speeds at least SOME of the time

The drives will only be getting used for storage of films, documents etc, and I won't be running applications or anything speed critical off them, so if they drop to FW400 speeds then that's not a big deal. Firewire has plenty of bandwidth, so I'm sure it'll be ok (i hope)

Thanks!

 

[Capt Underpants]

If you want to alleviate any potential bandwidth issues, purchase an firewire express card adapter.

Plug the hard drives into that, and let the motu have the bandwidth from the built-in port.

 

[codyst]

If you want to alleviate any potential bandwidth issues, purchase an firewire express card adapter.

Plug the hard drives into that, and let the motu have the bandwidth from the built-in port.

Reading the specs on that card it only talks about 400Mbps which leads me to assume it's only a FW400 card. So instead of plugging the hard drive into that he should put it in the built in port and plug the motu into the expresscard.

 

[bensonhedges]

If you want to alleviate any potential bandwidth issues, purchase an firewire express card adapter.

Plug the hard drives into that, and let the motu have the bandwidth from the built-in port.

BRILLIANT. Thankyou....this looks like exactly what I need.

As codyst already said, perhaps it'd be better to plug the Motu into this? If so, that'd be exactly what I need.

Has anyone used one of these Firewire Expresscards before? Are there any incompatibility issues? I've had compatibility issues when using a third party FW interface on a PC....

 

[dr. shdw]

1. Yes, you can do it.

2 and 3: Ok, first, there is only 1 FW bus in the MBP, so all 3 devices are going to be sharing one link. And yes, putting a FW400 device into the group will drop back the whole system to FW400, so you'd have all 3 devices on one FW400 bus. Whether or not that actually causes problems for you is going to depend on what you are doing at the time.

I thought FW could run independently at either 800 or 400 if you have both types of devices connected and will not default to the slowest.