Could your Fire Wire 400 Devices be degrading your Fire Wire 800 Devices? I WAS WRONG
UDATE: I was wrong in what I’ve said on this post. I tested this with a FW400 iSight external camera and my results for that are right. However today I restested this using two external hard drives (one FW400 and one FW800). I did no have any data rate loss at all. I will put out and updated screencast showing this. My apologies for the bad information. However if you are using a FW400 camera of some type I would check that because my test with the FW400 iSight did degrade the bus.
Thanks you
Victor
In this video I show you how your Fire Wire devices (like hard drives or old iSight cameras, even video cameras that use fire wire) could be degrading the throughput of your Fire Wire 800 devices.
The main point of this post is that there is only one (1) Fire Wire bus on our Macs and therefore if you use a FW400 device and a FW800 device it will always default to the lower speed , making the efficiency you get from FW800 mute.
Also I used an old Fire Wire 400 external iSight Camera for this test. The built in iSights on Macs today are USB NOT Fire Wire so nothing to worry about.
Here is some more discussion about this topic at ArsTechnica. I did not try every permutation of that is possible I based my findings on my limited testing.
Apple Developer notes on Fire Wire concepts
Apple Developer notes on MacPro Fire Wire bus architecture
