Problem: mounting multiple Firewire devices

amoergosum said:

I'm using a Mac Pro (early 2009) which has 4 Firewire ports.
Today I connected two Firewire Compact Flash readers. The first CF card mounted properly. When I put the second CF card in the second Firewire CF reader it caused both readers to crash.
Does anyone know what the problem is? Why is it not possible to connect two Firewire devices to two ports of the Mac Pro at the same time?

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It is possible to have all FW ports working and in Use, you might have bad Firewire Compact Flash readers.
First thing for you to check is if there is newer firmware and Drivers.

Btw, why do you have FW Card readers, are your cards faster than USB 2 speed?

amoergosum said:

The Firewire readers are working fine if I only connect one reader.
So it's not an issue related to the reader/firmware/driver .
As I mentioned...as soon as I connect the second FW reader and insert
a CF card both readers crash.



FW readers are a lot faster than USB 2.0 readers.

Click to expand...

About FW readers faster than USB 2 readers, this depends on the Card, if you have a slow card there won't be any difference.

I have 2 firewire HD's attached and never had problems, this on an Old PB 1.67 on 10.5.8

I historically have had issues with plugging multiple FW devices into my 2008 iMac. For instance, I have multiple FW800 HDDs attached to the iMac and they work fine. However, if I plug in a video camera and try to copy video from it to one of the FW800 drives, they crash. I must instead copy the video from the camera to my internal SSD, then from the internal SSD to the external FW800 drives.

"The Firewire readers which I use (Hama Traveldrive) have the same ID."

My guess (and it's _only_ a guess) is that the ID's are "hard-coded" into the readers and not changeable.

Thus, the conflict when you have them both on the chain at the same time.

Solution:
Keep one of them, remove the other.
Get a USB card reader as your "other reader".

Problem solved (yes, the USB reader will be a bit slower).

Just out of curiosity, what does the Console (Launchpad -> Utilities -> Console) say when you plug in the second reader?